The Grammys are over. Sam Smith has truly arrived on the international stage thanks to his four awards.
Beck was a surprise but well-deserved winner, while Pharrell and Beyonce continue to dominate the world of pop.
Performance highlights included Sia (even though she was facing a wall) and Pharrell (can the next album be full of pseudo European film soundtracks please?) Madonna returned, but needs to find a new way to shock.
There was also a serious undertone, with sections highlighting domestic abuse and civil rights.
With so much going on, we initially missed the split second when Kanye West rushed the stage when Beck was awarded the best album prize, beating Beyonce.
It was reminiscent of the incident when Kanye interrupted Taylor Swift at the MTV VMAs in 2009 after she beat Beyonce to best female video.
Kanye was apparently joking though, and walked away again.
There were some unlikely meetings of great musical minds both on stage and backstage at the Grammys.
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The defining hitmakers of two eras? Pharrell Williams and Sir Paul McCartney.
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Prince presented Beck with the album of the year trophy.
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Tortured Irish singer-songwriter Hozier didn't win an award - but a cuddle with Taylor Swift isn't a bad consolation.
Kristen Wiig's cameo
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Bridesmaids actress Kristen Wiig was one of the dancers during Sia's performance of Chandelier, alongside 12-year-old Maddie Ziegler. Definitely one of the performance highlights of the night.
Rousing rights message
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Beyonce has just been on stage singing a poignant version of gospel song Take My Hand, Precious Lord, which was a favourite of Martin Luther King and was performed at his funeral.
She has just introduced Glory, from the film Selma, which is about Dr Luther King. The song is being performed by John Legend and Common.
Sam style
Sam Smith has gone through three Beyonce-style outfit changes over the course of the evening.
He first started out in a black suit with a white bow tie, then a red suit, then a blue tartan-style three-piece. We're guessing it's the same shirt.
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Sam's the man
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The headlines will be about Sam Smith.
Accepting the record of the year prize, he said: "Dear Lord - thank you so much. Thank you to the academy, thank you all. This is the best night of my life.
"Just a quick one - I want to thank the man who this record is about, who I fell in love with last year. Thank you so much for breaking my heart because you got me four Grammys."
We've had all the awards - there still seem to be some performances to come though.
Post update
Record of the year - Sam Smith, Stay With Me (Darkchild version)
The score
Record of the year is the only award yet to be announced.
By my calculations, here are the running totals. No runaway winner this year, but I reckon Sam Smith might edge ahead:
Sam Smith - 3 awards
Pharrell - 3
Rosanne Cash - 3
Beyonce - 3
Beck - 2
Kendrick Lamar - 2
Eminem - 2
Chick Corea - 2
Song vs record
If you're wondering what the difference is between the awards for song and record of the year - song of the year is for the songwriters and record of the year is for the performers.
Four songs are nominated for both - Sia's Chandelier, Sam Smith's Stay With Me, Taylor Swift's Shake It Off and Meghan Trainor's All About That Bass.
Fancy by Iggy Azalea feat Charli XCX completes the record of the year shortlist. Hozier's Take Me To Church was the fifth song of the year nominee.
Post update
Song of the year - Sam Smith, James Napier and William Phillips, Stay With Me (Darkchild version)
Sia faces the music
Sia - the pop star whose gimmick is that she doesn't like being a pop star - is singing her hit Chandelier while facing a wall.
She's in a set that has been made to look like a grotty flat as two dancers bounce around and in a fabulous contemporary route.
Prime time performance art. Brilliant.
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Grammys - reaction
Jeremy Shink tweets: "Prince looks like a mix between a member of the Jackson 5 and a homeless woman."
Tanya J Smith: "Prince gets a standing ovation just walking out on stage- But of course."
khlokhlo: "Ugh Beck just beat Sam Smith and Beyonce ?! How?! Just how."
LV: "I would be very happy if Beyonce or Sam had win but Beck? No thanks."
Beck triumphs
A surprise result as long-serving indie troubadour Beck scoops the album of the year award for his 12th studio LP.
I never thought I would see Beck embracing Prince.
"We made this record at my house for the most part so I'd like to thank my kids," Beck says, alongside thanks to various other people.
He beat Beyonce, Ed Sheeran, Sam Smith and Pharrell Williams. Go Beck.
Post update
Album of the year - Beck, Morning Phase
It's album time
Here we go - Prince is here to announce album of the year - one of the biggies.
More awards please
I make it more than an hour since the last award was awarded.
I love Juanes (who's performing a jaunty number in Spanish now) as much as the next man, but could they not give out more than nine awards in a three-and-a-half hour award ceremony?
Sam Smith's star turn
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Sam Smith has that "Oh my God am I really singing at the Grammys" look in his eyes as he sings a gorgeous version of his hit Stay With Me with Mary J Blige, backed by a large string section.
I was hoping for a duet between Sam Smith and Tom Petty on a medley of Stay With Me and I Won't Back Down, but I guess that's not going to happen.
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McKanyhanna
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Now that's what I call a supergroup.
After country stars Eric Church and Brandy Clark, the camera cuts to Sir Paul McCartney, Kanye West and Rihanna performing their collaboration FourFiveSeconds in front of a plain backdrop.
Sir Macca was strumming along and singing backing vocals and looked like he wanted to launch into Back in the USSR when the song finished and the camera cut away to an ad. A bit of a waste of a Beatle.
I would have liked to have seen Kanye and Rihanna sing backing vocals on Back in the USSR.
Grammys - reaction
MH tweets: "Guys Kayne is so kind helping this guy.. his name is Paul McCartney or something?! a real up & comer!"
Juan G Gusart: "Is it me or these Grammy's except AC/DC has been all ballads?"
Mike Thompson: "Tough call on pop song of year, but Chandelier by @Sia was so tremendous I would've liked to have seen it win."
Morgan Johnston: "I'd like to thank the #Grammys' Sleepy-Time Music Special for ensuring we'll all be tucked in and well rested for work tomorrow."
Ian Denton: "I'm about #FourFiveSeconds from sleeping, these #GRAMMYs are boring me the death."
US President Barack Obama
@BarackObama
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"Watch the message that aired tonight during the #Grammys from President Obama: #ItsOnUs to stop sexual assault."
Stripped back songs
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I'm not sure if they've cut the Grammys budget this year, but Pharrell and Madonna have been the only big numbers with lots of dancers and there have been quite a few stripped-back performances.
I'm sure they'd say it's all about the music and the voice.
Lady Gaga and Tony Bennett have just been on, looking stylish as they sang a swinging version of Irving Berlin's Cheek To Cheek.
Usher's on now, accompanied only by a harp and a short but sweet cameo from Stevie Wonder's harmonica.
Abuse message
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One of the most moving sections of the ceremony was not a performance by another rich and famous pop star - it was the speech about domestic abuse by Brooke Axtell, from Austin, Texas.
She spoke about her "romance with a handsome, charismatic man".
"I was stunned when he began to abuse me," she continued. "Authentic love does not devalue another human being. Authentic love does not silence, shame or abuse."
Katy Perry then followed her Super Bowl shenanigans last weekend with a more solemn performance, singing her ballad By the Grace of God.
She and Axtell got a standing ovation.
Obama's appeal
A surprise appearance from US President Barack Obama - on a screen - to introduce a segment aimed at helping those suffering domestic violence.
"It's not OK and it has to stop," he said. "Artists have a unique power to change minds and attitudes and get us talking about what matters."
He urged people to support the campaign by visiting ItsOnUs.org before a survivor of abuse, Brooke Axtell, took to the stage to tell her story.
Pharrell's Happy clappy
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Best performance of the night so far - Pharrell Williams joined forces with composer Hans Zimmer and pianist Lang Lang to turn Happy into an epic, European-flavoured hymnal celebration.
It started with Pharrell reciting the opening lines from his song in sombre tones, with other voices speaking what I assume were European translations. Then dramatic, soundtrack-style strings kicked in - presumably Zimmer's contribution.
It was a bit of a shame when the tempo and key picked up and the normal version kicked in, to be honest.
Annie's spell
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The next superstar collaboration was between Irish singer Hozier and Annie Lennox.
Hozier's anthem about obsessive romance Take Me To Church morphed into Annie singing I Put A Spell On You, which seemed to feature the former Eurythmic playing air harmonica.
Post update
Best country album - Miranda Lambert, Platinum
Gwen and Adam duet
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For a performance "everyone will be talking about tomorrow" (we were promised), the rendition of Maroon 5's My Heart Is Open by The Voice co-stars Gwen Stefani and Adam Levine was a tad underwhelming.
After that build-up, I was expecting pyrotechnics and acrobats - but I'm being churlish. It was an excellent vocal performance.
Ed Sheeran performed his hit Thinking Out Loud before joining ELO's Jeff Lynne for Evil Woman and Mr Blue Sky.
Sir Paul McCartney, Taylor Swift and that renowned pop star Nicole Kidman were grooving along in the audience.
(Well, she did release a single with Robbie Williams in 2001.)
Corden introduces Sheeran
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British comedian James Corden - who is taking over from Craig Ferguson as host of The Late Late Show in the US - just appeared to introduce Ed Sheeran.
Despite having hosted the Brit Awards for several years, he made a slightly nervous start to his link.
He went on to take credit for Ed's big break, having tweeted a link to his music while the singer was still unsigned. Ed owes him one.
Beyonce and Jay-Z 4 Ever
That's Beyonce's third award of the night. "I'd like to thank my beloved husband," she said. "I love you deep."
Post update
Best R&B performance - Beyonce feat Jay-Z, Drunk in Love
Coming up - a duet between Gwen Stefani and Maroon 5's Adam Levine which apparently "everyone will be talking about tomorrow".
Typical Madonna
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Madonna, on the other hand, has a big production - she is touching herself suggestively on a podium with a couple of dozen half-naked male dancers wearing glittering masks and horns.
Good old Madonna.
She's singing Living For Love, from her new album Rebel Heart.
Kanye's first appearance
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The stage is black, save for Kanye West uplit by a single beam and some dry ice. He's singing Only One, which he wrote with Sir Paul McCartney.
He's due to return to perform with Sir Paul and Rihanna later.
AC/DC karaoke
The Hollywood Reporter's Matthew Belloni has tweeted a picture giving away AC/DC's secret - they used a teleprompter for their opening number. Their set didn't please everyone though, judging by the gentleman at the front.
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Sam's second win
Best pop vocal album - Sam Smith, In the Lonely Hour
That is Sam Smith's second win of the night, and he gave a touching speech about how he had tried to make it for years and had tried to lose weight to become a pop star.
"It was only until I started to be myself that the music flowed and people started to listen," he said.
Pharrell's shorts
Here are Pharrell's outfits. One outfit for the red carpet is clearly not enough.
Pharrell collected his third award of the night wearing a suit with shorts. He likes to make a fashion statement - remember the hat at last year's Grammys?
He said: "I'm not going to make this awkward and long because I was so prepared for everybody else that is so talented in that category to walk away with that award. I'm honoured to be grouped with them."
The other nominees were Sia, John Legend, Sam Smith and Taylor Swift.
Post update
Best pop solo performance - Happy (Live), Pharrell Williams
The Voice reunion
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Jessie J and Sir Tom Jones - who worked together as judges on The Voice UK - have just belted out You've Lost That Lovin' Feelin'.
It's in tribute to songwriters Barry Mann and Cynthia Weil, who co-wrote that song and have received the Grammy Trustees' Award.
Red carpet style
Rihanna wins the award for wearing the most fabric in a dress.
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Sam Smith on stage
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Here's Sam Smith getting his trophy for best new artist.
He beat Iggy Azalea, Bastille, Brandy Clark and Haim.
Ariana's grand
Host LL Cool J said there will be 23 performances - AC/DC were first, and now Ariana Grande is #2, performing Just A Little Bit of Your Heart accompanied by a grand piano and wearing what looks like a diamond-encrusted earpiece.
Mad Diva prize
The late Joan Rivers won best spoken word album for Diary of a Mad Diva and her daughter, Melissa Rivers, was on hand to accept the Grammy.
"If my mother was here tonight, she would not only be honoured and thrilled to be holding her first Grammy, she would most likely have it copied and on the air on QVC by 11," she joked.
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Sam's off the mark
"Oh my gosh. I've got to try to say something now without crying. Thank you."
Sam Smith is getting emotional already and the night's only just begun. He went on to thank his mum and dad. "I won a Grammy!"
Post update
Best new artist - Sam Smith
First big award
Taylor Swift is announcing the first award - best new artist. She lost this award in 2008 and look where she is now...
Show time!
A very excitable LL Cool J introduced rockers AC/DC to open the ceremony. A quick camera shot at Jamie Foxx shows him nodding in approval.
Tweet @BBCNewsEnts or email entertainment.news@bbc.co.uk
Genevieve Hassan
Entertainment reporter
If you're staying up to follow our Grammys coverage, get in touch and let us know who you think will win. What do you make of the winners so far? Tweet or email us!
Red carpet photos
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Australian singer Sia (right), whose claim to fame is that she doesn't want to be famous, turned up with 12-year-old dancer Maddie Ziegler.
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Ariana Grande is here with boyfriend Big Sean.
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Gwen Stefani, former coach on The Voice US, will be performing with fellow coach Adam Levine.
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Pharrell Williams (still rocking his formal shorts attire) arrived with his wife Helen Lasichanh.
More early winners
Here are some more winners from the preliminary ceremony:
Best traditional pop vocal album: Tony Bennett & Lady Gaga - Cheek To Cheek
Best rock performance: Jack White - Lazaretto
Best rock song: Paramore - Ain't It Fun
Best alternative rock album: St. Vincent - St. Vincent
Best metal performance: Tenacious D - The Last In Line
Brits off the mark
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A couple of Brits have scooped awards during the preliminary ceremony.
Congratulations to Clean Bandit and Jess Glynne (above), who won best dance recording for Rather Be.
That was a Brit-heavy category - they beat Basement Jaxx, Disclosure, Duke Dumont and (token non-Brit) Zhu.
And dance veteran Aphex Twin won best dance/electronic album for Syro, his first album for 13 years.
Pace setters
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The pace has been set by Rosanne Cash (Johnny's daughter), who has scooped three early trophies - best American roots performance, best American roots song and best Americana album.
Other multiple winners so far include Eminem, who's won best rap/sung collaboration for The Monster (with Rihanna) and best rap album (The Marshall Mathers LP2).
Kendrick Lamar also has a double already - best rap song and best rap performance, both for I.
Madonna's back
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Madonna's arrived and is clearly determined not to get overshadowed by the younger pop crowd.
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Pharrell v Beyonce
Pharrell and Beyonce have an early head start, each winning two awards during the preliminary ceremony, where 74 of the 83 awards were handed out before the main televised extravaganza begins.
Pharrell won best urban contemporary album for Girl and best music video for Happy.
Beyonce won best R&B song for Drunk In Love (feat Jay-Z) and the big one - best surround sound album for her self-titled record, Beyonce.
Grammy time!
Ian Youngs
Entertainment reporter
Hi - welcome to our rolling coverage of the 57th Grammy Awards, which are taking place in LA.
The main ceremony kicks off at 01:00 GMT - but many of the 83 awards have been handed out at a pre-ceremony bash.
We'll fill you in on who's won so far, the latest from the red carpet and all the action when the main event gets under way.
British singer Sam Smith is hotly tipped to take home the most trophies - but he faces stiff competition from Beyonce and Pharrell Williams.
Live Reporting
Ian Youngs and Genevieve Hassan
All times stated are UK
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Getty ImagesCopyright: Getty Images - Sam Smith - 3 awards
- Pharrell - 3
- Rosanne Cash - 3
- Beyonce - 3
- Beck - 2
- Kendrick Lamar - 2
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Getty ImagesCopyright: Getty Images - Best traditional pop vocal album: Tony Bennett & Lady Gaga - Cheek To Cheek
- Best rock performance: Jack White - Lazaretto
- Best rock song: Paramore - Ain't It Fun
- Best alternative rock album: St. Vincent - St. Vincent
- Best metal performance: Tenacious D - The Last In Line
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Latest PostGrammy highlights
Ian Youngs
Entertainment reporter
The Grammys are over. Sam Smith has truly arrived on the international stage thanks to his four awards.
Beck was a surprise but well-deserved winner, while Pharrell and Beyonce continue to dominate the world of pop.
Performance highlights included Sia (even though she was facing a wall) and Pharrell (can the next album be full of pseudo European film soundtracks please?) Madonna returned, but needs to find a new way to shock.
There was also a serious undertone, with sections highlighting domestic abuse and civil rights.
I'm now going to continue writing our main news story. You can also see a list of key winners and a picture gallery. Good night.
Kanye does it again
With so much going on, we initially missed the split second when Kanye West rushed the stage when Beck was awarded the best album prize, beating Beyonce.
It was reminiscent of the incident when Kanye interrupted Taylor Swift at the MTV VMAs in 2009 after she beat Beyonce to best female video.
Kanye was apparently joking though, and walked away again.
Beyonce and Jay-Z's reaction to the stunt was priceless.
Grammy double acts
There were some unlikely meetings of great musical minds both on stage and backstage at the Grammys.
The defining hitmakers of two eras? Pharrell Williams and Sir Paul McCartney.
Prince presented Beck with the album of the year trophy.
Tortured Irish singer-songwriter Hozier didn't win an award - but a cuddle with Taylor Swift isn't a bad consolation.
Kristen Wiig's cameo
Bridesmaids actress Kristen Wiig was one of the dancers during Sia's performance of Chandelier, alongside 12-year-old Maddie Ziegler. Definitely one of the performance highlights of the night.
Rousing rights message
Beyonce has just been on stage singing a poignant version of gospel song Take My Hand, Precious Lord, which was a favourite of Martin Luther King and was performed at his funeral.
She has just introduced Glory, from the film Selma, which is about Dr Luther King. The song is being performed by John Legend and Common.
Sam style
Sam Smith has gone through three Beyonce-style outfit changes over the course of the evening.
He first started out in a black suit with a white bow tie, then a red suit, then a blue tartan-style three-piece. We're guessing it's the same shirt.
Sam's the man
The headlines will be about Sam Smith.
Accepting the record of the year prize, he said: "Dear Lord - thank you so much. Thank you to the academy, thank you all. This is the best night of my life.
"Just a quick one - I want to thank the man who this record is about, who I fell in love with last year. Thank you so much for breaking my heart because you got me four Grammys."
We've had all the awards - there still seem to be some performances to come though.
Post update
Record of the year - Sam Smith, Stay With Me (Darkchild version)
The score
Record of the year is the only award yet to be announced.
By my calculations, here are the running totals. No runaway winner this year, but I reckon Sam Smith might edge ahead:
Song vs record
If you're wondering what the difference is between the awards for song and record of the year - song of the year is for the songwriters and record of the year is for the performers.
Four songs are nominated for both - Sia's Chandelier, Sam Smith's Stay With Me, Taylor Swift's Shake It Off and Meghan Trainor's All About That Bass.
Fancy by Iggy Azalea feat Charli XCX completes the record of the year shortlist. Hozier's Take Me To Church was the fifth song of the year nominee.
Post update
Song of the year - Sam Smith, James Napier and William Phillips, Stay With Me (Darkchild version)
Sia faces the music
Sia - the pop star whose gimmick is that she doesn't like being a pop star - is singing her hit Chandelier while facing a wall.
She's in a set that has been made to look like a grotty flat as two dancers bounce around and in a fabulous contemporary route.
Prime time performance art. Brilliant.
Grammys - reaction
Jeremy Shink tweets: "Prince looks like a mix between a member of the Jackson 5 and a homeless woman."
Tanya J Smith: "Prince gets a standing ovation just walking out on stage- But of course."
khlokhlo: "Ugh Beck just beat Sam Smith and Beyonce ?! How?! Just how."
LV: "I would be very happy if Beyonce or Sam had win but Beck? No thanks."
Beck triumphs
A surprise result as long-serving indie troubadour Beck scoops the album of the year award for his 12th studio LP.
I never thought I would see Beck embracing Prince.
"We made this record at my house for the most part so I'd like to thank my kids," Beck says, alongside thanks to various other people.
He beat Beyonce, Ed Sheeran, Sam Smith and Pharrell Williams. Go Beck.
Post update
Album of the year - Beck, Morning Phase
It's album time
Here we go - Prince is here to announce album of the year - one of the biggies.
More awards please
I make it more than an hour since the last award was awarded.
I love Juanes (who's performing a jaunty number in Spanish now) as much as the next man, but could they not give out more than nine awards in a three-and-a-half hour award ceremony?
Sam Smith's star turn
Sam Smith has that "Oh my God am I really singing at the Grammys" look in his eyes as he sings a gorgeous version of his hit Stay With Me with Mary J Blige, backed by a large string section.
I was hoping for a duet between Sam Smith and Tom Petty on a medley of Stay With Me and I Won't Back Down, but I guess that's not going to happen.
E! Online
@eonline
McKanyhanna
Now that's what I call a supergroup.
After country stars Eric Church and Brandy Clark, the camera cuts to Sir Paul McCartney, Kanye West and Rihanna performing their collaboration FourFiveSeconds in front of a plain backdrop.
Sir Macca was strumming along and singing backing vocals and looked like he wanted to launch into Back in the USSR when the song finished and the camera cut away to an ad. A bit of a waste of a Beatle.
I would have liked to have seen Kanye and Rihanna sing backing vocals on Back in the USSR.
Grammys - reaction
MH tweets: "Guys Kayne is so kind helping this guy.. his name is Paul McCartney or something?! a real up & comer!"
Juan G Gusart: "Is it me or these Grammy's except AC/DC has been all ballads?"
Mike Thompson: "Tough call on pop song of year, but Chandelier by @Sia was so tremendous I would've liked to have seen it win."
Morgan Johnston: "I'd like to thank the #Grammys' Sleepy-Time Music Special for ensuring we'll all be tucked in and well rested for work tomorrow."
Ian Denton: "I'm about #FourFiveSeconds from sleeping, these #GRAMMYs are boring me the death."
US President Barack Obama
@BarackObama
"Watch the message that aired tonight during the #Grammys from President Obama: #ItsOnUs to stop sexual assault."
Stripped back songs
I'm not sure if they've cut the Grammys budget this year, but Pharrell and Madonna have been the only big numbers with lots of dancers and there have been quite a few stripped-back performances.
I'm sure they'd say it's all about the music and the voice.
Lady Gaga and Tony Bennett have just been on, looking stylish as they sang a swinging version of Irving Berlin's Cheek To Cheek.
Usher's on now, accompanied only by a harp and a short but sweet cameo from Stevie Wonder's harmonica.
Abuse message
One of the most moving sections of the ceremony was not a performance by another rich and famous pop star - it was the speech about domestic abuse by Brooke Axtell, from Austin, Texas.
She spoke about her "romance with a handsome, charismatic man".
"I was stunned when he began to abuse me," she continued. "Authentic love does not devalue another human being. Authentic love does not silence, shame or abuse."
Katy Perry then followed her Super Bowl shenanigans last weekend with a more solemn performance, singing her ballad By the Grace of God.
She and Axtell got a standing ovation.
Obama's appeal
A surprise appearance from US President Barack Obama - on a screen - to introduce a segment aimed at helping those suffering domestic violence.
"It's not OK and it has to stop," he said. "Artists have a unique power to change minds and attitudes and get us talking about what matters."
He urged people to support the campaign by visiting ItsOnUs.org before a survivor of abuse, Brooke Axtell, took to the stage to tell her story.
Pharrell's Happy clappy
Best performance of the night so far - Pharrell Williams joined forces with composer Hans Zimmer and pianist Lang Lang to turn Happy into an epic, European-flavoured hymnal celebration.
It started with Pharrell reciting the opening lines from his song in sombre tones, with other voices speaking what I assume were European translations. Then dramatic, soundtrack-style strings kicked in - presumably Zimmer's contribution.
It was a bit of a shame when the tempo and key picked up and the normal version kicked in, to be honest.
Annie's spell
The next superstar collaboration was between Irish singer Hozier and Annie Lennox.
Hozier's anthem about obsessive romance Take Me To Church morphed into Annie singing I Put A Spell On You, which seemed to feature the former Eurythmic playing air harmonica.
Post update
Best country album - Miranda Lambert, Platinum
Gwen and Adam duet
For a performance "everyone will be talking about tomorrow" (we were promised), the rendition of Maroon 5's My Heart Is Open by The Voice co-stars Gwen Stefani and Adam Levine was a tad underwhelming.
After that build-up, I was expecting pyrotechnics and acrobats - but I'm being churlish. It was an excellent vocal performance.
Lady Gaga with Tony
@ladygaga
"AC/DC was killer can't wait to see Beck and Sam Smith!"
Sam Smith with Taylor Swift
@samsmithworld
"What is my life."
Ed's Light Orchestra
Ed Sheeran performed his hit Thinking Out Loud before joining ELO's Jeff Lynne for Evil Woman and Mr Blue Sky.
Sir Paul McCartney, Taylor Swift and that renowned pop star Nicole Kidman were grooving along in the audience.
(Well, she did release a single with Robbie Williams in 2001.)
Corden introduces Sheeran
British comedian James Corden - who is taking over from Craig Ferguson as host of The Late Late Show in the US - just appeared to introduce Ed Sheeran.
Despite having hosted the Brit Awards for several years, he made a slightly nervous start to his link.
He went on to take credit for Ed's big break, having tweeted a link to his music while the singer was still unsigned. Ed owes him one.
Beyonce and Jay-Z 4 Ever
That's Beyonce's third award of the night. "I'd like to thank my beloved husband," she said. "I love you deep."
Post update
Best R&B performance - Beyonce feat Jay-Z, Drunk in Love
Grammys backstage
@TheGRAMMYs
Backstage with Madonna.
Post update
Best rock album - Morning Phase, Beck
Post update
Coming up - a duet between Gwen Stefani and Maroon 5's Adam Levine which apparently "everyone will be talking about tomorrow".
Typical Madonna
Madonna, on the other hand, has a big production - she is touching herself suggestively on a podium with a couple of dozen half-naked male dancers wearing glittering masks and horns.
Good old Madonna.
She's singing Living For Love, from her new album Rebel Heart.
Kanye's first appearance
The stage is black, save for Kanye West uplit by a single beam and some dry ice. He's singing Only One, which he wrote with Sir Paul McCartney.
He's due to return to perform with Sir Paul and Rihanna later.
AC/DC karaoke
The Hollywood Reporter's Matthew Belloni has tweeted a picture giving away AC/DC's secret - they used a teleprompter for their opening number. Their set didn't please everyone though, judging by the gentleman at the front.
Sam's second win
Best pop vocal album - Sam Smith, In the Lonely Hour
That is Sam Smith's second win of the night, and he gave a touching speech about how he had tried to make it for years and had tried to lose weight to become a pop star.
"It was only until I started to be myself that the music flowed and people started to listen," he said.
Pharrell's shorts
Here are Pharrell's outfits. One outfit for the red carpet is clearly not enough.
Pharrell 'honoured'
Pharrell collected his third award of the night wearing a suit with shorts. He likes to make a fashion statement - remember the hat at last year's Grammys?
He said: "I'm not going to make this awkward and long because I was so prepared for everybody else that is so talented in that category to walk away with that award. I'm honoured to be grouped with them."
The other nominees were Sia, John Legend, Sam Smith and Taylor Swift.
Post update
Best pop solo performance - Happy (Live), Pharrell Williams
The Voice reunion
Jessie J and Sir Tom Jones - who worked together as judges on The Voice UK - have just belted out You've Lost That Lovin' Feelin'.
It's in tribute to songwriters Barry Mann and Cynthia Weil, who co-wrote that song and have received the Grammy Trustees' Award.
Red carpet style
Rihanna wins the award for wearing the most fabric in a dress.
Sam Smith on stage
Here's Sam Smith getting his trophy for best new artist.
He beat Iggy Azalea, Bastille, Brandy Clark and Haim.
Ariana's grand
Host LL Cool J said there will be 23 performances - AC/DC were first, and now Ariana Grande is #2, performing Just A Little Bit of Your Heart accompanied by a grand piano and wearing what looks like a diamond-encrusted earpiece.
Mad Diva prize
The late Joan Rivers won best spoken word album for Diary of a Mad Diva and her daughter, Melissa Rivers, was on hand to accept the Grammy.
"If my mother was here tonight, she would not only be honoured and thrilled to be holding her first Grammy, she would most likely have it copied and on the air on QVC by 11," she joked.
Sam's off the mark
"Oh my gosh. I've got to try to say something now without crying. Thank you."
Sam Smith is getting emotional already and the night's only just begun. He went on to thank his mum and dad. "I won a Grammy!"
Post update
Best new artist - Sam Smith
First big award
Taylor Swift is announcing the first award - best new artist. She lost this award in 2008 and look where she is now...
Show time!
A very excitable LL Cool J introduced rockers AC/DC to open the ceremony. A quick camera shot at Jamie Foxx shows him nodding in approval.
Grammys - Red carpet
@TheGRAMMYs
Queen B has arrived!
Campbell absence
Glen Campbell's I'm Not Gonna Miss You, from his documentary I'll Be Me, has won best country song.
The singer, who is battling Alzheimer's disease, didn't attend the Grammy ceremony.
"I am just so proud of him tonight, he's been so courageous," his wife Kim Campbell said on stage.
"Sadly, he can't be here with us because he's in the late stages." She added: "Music, I really believe, kept him healthy."
On the red carpet
Jaime Gonzalez
BBC Mundo, Los Angeles
#SamSmith Live from the red carpet at the #Grammys2015
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Genevieve Hassan
Entertainment reporter
If you're staying up to follow our Grammys coverage, get in touch and let us know who you think will win. What do you make of the winners so far? Tweet or email us!
Red carpet photos
Australian singer Sia (right), whose claim to fame is that she doesn't want to be famous, turned up with 12-year-old dancer Maddie Ziegler.
Ariana Grande is here with boyfriend Big Sean.
Gwen Stefani, former coach on The Voice US, will be performing with fellow coach Adam Levine.
Pharrell Williams (still rocking his formal shorts attire) arrived with his wife Helen Lasichanh.
More early winners
Here are some more winners from the preliminary ceremony:
Brits off the mark
A couple of Brits have scooped awards during the preliminary ceremony.
Congratulations to Clean Bandit and Jess Glynne (above), who won best dance recording for Rather Be.
That was a Brit-heavy category - they beat Basement Jaxx, Disclosure, Duke Dumont and (token non-Brit) Zhu.
And dance veteran Aphex Twin won best dance/electronic album for Syro, his first album for 13 years.
Pace setters
The pace has been set by Rosanne Cash (Johnny's daughter), who has scooped three early trophies - best American roots performance, best American roots song and best Americana album.
Other multiple winners so far include Eminem, who's won best rap/sung collaboration for The Monster (with Rihanna) and best rap album (The Marshall Mathers LP2).
Kendrick Lamar also has a double already - best rap song and best rap performance, both for I.
Madonna's back
Madonna's arrived and is clearly determined not to get overshadowed by the younger pop crowd.
Pharrell v Beyonce
Pharrell and Beyonce have an early head start, each winning two awards during the preliminary ceremony, where 74 of the 83 awards were handed out before the main televised extravaganza begins.
Pharrell won best urban contemporary album for Girl and best music video for Happy.
Beyonce won best R&B song for Drunk In Love (feat Jay-Z) and the big one - best surround sound album for her self-titled record, Beyonce.
Grammy time!
Ian Youngs
Entertainment reporter
Hi - welcome to our rolling coverage of the 57th Grammy Awards, which are taking place in LA.
The main ceremony kicks off at 01:00 GMT - but many of the 83 awards have been handed out at a pre-ceremony bash.
We'll fill you in on who's won so far, the latest from the red carpet and all the action when the main event gets under way.
British singer Sam Smith is hotly tipped to take home the most trophies - but he faces stiff competition from Beyonce and Pharrell Williams.