SAM Smith was the undisputed winner of today's Grammy Awards.

The British crooner took home four awards including Record of the Year and Song of the Year.

"I want to thank the man who this record is about. Thank you for breaking my heart because you got me four Grammys," Smith said, referring to his album's title track, Stay With Me.

In what he described as the "best night" of his life, Smith also won Best New Artist and Best Pop Vocal Album and performed with idol Mary J Blige.

 "Before I made this record I was doing everything to try and get my music heard," he said, when accepting the award for Best Pop Vocal Album.

"I tried to lose weight and I was making awful music. It was only until I started to be myself that the music started to flow and people started to listen."

The singer's upcoming six-date Australian tour in April is already sold out everywhere except Perth.

Smith's wins meant Aussies Sia Furler and Iggy Azalea missed out on awards.

Azalea told Ryan Seacrest on the red carpet that she felt most honoured by her Best New Artist nomination.

"You only get to be nominated once," she said.

"I feel very stable now. I feel more secure in taking risks for that's good and very exciting when you're doing your second album… and Fancy gave me that confidence in what I'm doing."

LL Cool J hosted the 57^th annual awards from LA's Staples Centre.

Aussie rockers AC/DC started the awards with their first ever Grammy performance and the entire star-studded arena was on its feet.

Adelaide native Sia performed her hit Chandelier, facing away from the audience as young dancer Maddie Ziegler and actor Kristen Wiig danced in her signature blonde bob wigs.

American music's night of nights also included performances by Madonna, Ariana Grande, Kanye West, Katy Perry, Pharrell Williams and Ed Sheeran.

Grammy winners:

Record of the Year

Stay With Me, Sam Smith

Album of the Year

Morning Phase, Beck

Song of the Year

Stay With Me, Sam Smith

Best New Artist

Sam Smith

Best Pop Solo Performance

Pharrell Williams, Happy

Best Pop Vocal Album

In The Lonely Hour, Sam Smith

Best Rock Album

Morning Phase, Beck

Best R&B Performance

Drunk In Love, Beyonce featuring Jay Z

Best Country Album

Platinum, Miranda Lambert

Best Pop Duo/Group Performance

Say Something, A Great Big World with Christina Aguilera

Best Traditional Pop Vocal Album

Cheek to Cheek, Tony Bennett and Lady Gaga

Best Dance Recording

Rather Be, Clean Bandit featuring Jess Glynne

Best Dance/Electronic Album

Syro, Aphex Twin

Best Contemporary Instrumental Album

Bass & Mandolin, Chris Thile and Edgar Meyer

Best Rock Performance

Lazaretto, Jack White

Best Metal Performance

The Last in Line, Tenacious D

Best Rock Song

Ain't It Fun, Paramore

Best Alternative Music Album

St Vincent, St Vincent

Best R&B Song

Drunk In Love, Beyonce featuring Jay Z

Best Urban Contemporary Album

Girl, Pharrell Williams

Best Traditional R&B Performance

Jesus Children, Robert Glasper Experiment

Best R&B Album

Love, Marriage & Divorce, Toni Braxton and Babyface

Best Rap Performance

I, Kendrick Lamar

Best Rap/Sung Collaboration

The Monster, Eminem featuring Rihanna

Best Rap Song

I, Kendrick Lamar

Best Rap Album

The Marshall Mathers LP2, Eminem

Best Country Solo Performance

Something In The Water, Carrie Underwood

Best Country Duo/Group Performance

Gentle on my Mind, The Band Perry

Best Country Song

I'm Not Gonna Miss You, Glen Campbell & Julian Raymond

Best New Age Album

Winds of Samsara, Ricky Kej & Wouter Kellerman

Best Improvised Jazz Solo

Fingerprints, Chick Corea

Best Jazz Vocal Album

Beautiful Life, Dianne Reeves

Best Jazz Instrumental Album

Trilogy, Chick Corea Trio

Best Large Jazz Ensemble Album

Life in the Bubble, Gordon Goodwin's Big Phat Band

Best Latin Jazz Album

The Offense of the Drum, Arturo O'Farrill & The Afro Latin Jazz Orchestra

Best Gospel Performance/Song

No Greater Love, Smokie Norful

Best Contemporary Christian Music Performance/Song

Messengers, Lecrae featuring For King & Country

Best Gospel Album

Help, Erica Campbell

Best Contemporary Christian Music Album

Run Wild. Live Free. Love Strong, For King & Country

Best Roots Gospel Album

Shine for All The People, Mike Farris

Best Latin Pop Album

Tangos, Ruben Blades

Best Latin Rock, Urban or Alternative Album

Multiviral, Calle 13

Best Regional Mexican Music Album

Mano A Mano - Tango A La Manera De Vicente Fernandez

Best Tropical Latin Album

Mas + Corazon Profundo, Carlos Vives

Best Bluegrass Album

The Earls of Leicester

Best Blues Album

Step Back, Johnny Winter

Best Regional Roots Music Album

The Legacy, Jo-El Sonnier

Best Reggae Album

Fly Rasta, Ziggy Marley

Best World Music Album

Eve, Angelique Kidjo

Best Children's Album

I Am Malala: How One Girl Stood up for Education and Changed the World

Best Spoken Word Album

Diary of a Mad Diva, Joan Rivers

Best Comedy Album

Mandatory Fun, Weird Al Yankovic

Best Musical Theatre Album

Beautiful: The Carole King Musical

Best Compilation Soundtrack for Visual Media

Frozen, Walt Disney Records

Best Score Soundtrack for Visual Media

The Grand Budapest Hotel, Alexandre Desplat

Best Song Written for Visual Media

Let It Go, Frozen soundtrack

Best Instrumental Composition

The Book Thief, John Williams

Best Arrangement, Instrumental or A Cappella

Daft Punk arranged by Pentatonix

Best Arrangement, Instruments and Vocals

New York Tendaberry

Best Recording Package

Lightning Bolt

Best Boxed or Special Limited Edition Package

The Rise & Fall of Paramount Records, Volume One

Best Album Notes

Offering: Live at Temple University

Best Historical Album

The Garden Spot Programs, 1950

Best Engineered Album, Non-Classical

Morning Phase

Best Remixed Recording, Non-Classical

All of Me (Tiesto's Birthday Treatment Remix)

Best Surround Sound Album

Beyonce

Best Engineered Album, Classical

Vaughan Williams: Dona Nobis Pacem, Symphony No 4, The Lark Ascending

Producer of the Year, Classical

Judith Sherman

Best Orchestral Performance

John Adams: City Noir

Best Opera Recording

Charpentier: La Descente D'Orphee Aux Enfers

Best Choral Performance

The Sacred Spirit of Russia

Best Chamber Music/Small Ensemble Performance

In 27 Pieces - The Hilary Hahn Encores

Best Classical Instrumental Solo

Play: Jason Vieaux

Best Classical Solo Vocal Album

Douce France

Best Classical Compendium

Partch: Plectra & Percussion Dances

Best Contemporary Classical Composition

John Luther Adams: Become Ocean

Best Music Video

Happy: Pharrell Williams

Best Music Film

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