French electro duo Daft Punk were among early winners, taking the prizes for best dance/electronica album and sound engineering in a pre-show segment before the three-hour telecast starting from 5:00 pm (0100 GMT).
Older acts were also up for honors at music's version of the Oscars, among them the Rolling Stones, Black Sabbath and the Beatles, whose surviving members were due to perform.
Led Zeppelin won best rock album for "Celebration Day," recorded at their 2007 live reunion show at London's O2 Arena, in the pre-telecast section of the show, while the Gipsy Kings and South Africa's Ladysmith Black Mambazo shared the world music Grammy.
Rapper Kendrick Lamar, pop diva Taylor Swift, chart-topper Justin Timberlake and Seattle hip hop duo Macklemore & Ryan Lewis are also among those vying for prizes at the show in Los Angeles.
The show was set to feature some eye-popping collaborations, including rockers Metallica with acclaimed Chinese pianist Lang Lang and Lamar with rock group Imagine Dragons.
In another likely spectacular moment, 34 couples were expected to marry during Macklemore & Ryan Lewis's performance of their song "Same Love," which uses rap to tackle the issue of same-sex marriage, according to media reports.
Surviving Beatles Paul McCartney and Ringo Starr were due to perform as Recording Academy organizers belatedly bestow a Lifetime Achievement Award on the Fab Four.
Performers at the awards show include a who's who of music's finest, ranging from Katy Perry and Robin Thicke to veterans Carole King, Chicago and Madonna.
The first couple of hip-hop, Jay-Z and Beyonce, are also expected to perform at the show, brought forward from its usual February date to avoid media conflicts with the Sochi Winter Olympics.
Many of the stars turned out Saturday night for legendary music producer Clive Davis's annual pre-Grammys party at the Beverly Hilton hotel -- where pop icon Whitney Houston died in her hotel bathroom on the eve of the 2012 show.
Going into Sunday's show, Jay-Z scored the most nominations with nine nods, followed by California hip-hop star Lamar, Macklemore & Ryan Lewis, Timberlake and Pharrell Williams with seven each, while Canadian rapper Drake scored five.
Tipped by many for coveted Record Of The Year was Daft Punk's "Get Lucky," but rival nominees include Kiwi teenager Lorde's "Royals," "Radioactive" by Imagine Dragons and Hawaiian crooner Bruno Mars's "Locked Out Of Heaven."
Thicke's "Blurred Lines," made infamous by Miley Cyrus's twerking at last year's MTV Video Music Awards show, is also competing for the evening's top prize.
In the Album of the Year category, Swift's "Red" will compete with Daft Punk's "Random Access Memories," Macklemore & Ryan Lewis's "The Heist," Lamar's "Good Kid, M.A.A.D City" and Sara Bareilles's "The Blessed Unrest."
Shortlisted for Song of the Year -- for songwriters -- were "Just Give Me A Reason" sung by Pink, "Locked Out Of Heaven" sung by Mars, "Roar" sung by Perry, "Royals" sung by Lorde and "Same Love" sung by Macklemore & Ryan Lewis.
Macklemore & Ryan Lewis was also nominated for Best New Artist, against Lamar, country singer Kacey Musgraves and British singer-songwriters James Blake and Ed Sheeran.
Among older stars, Best Rock Song contenders included "God is Dead?" by Black Sabbath, "Doom and Gloom" by the Rolling Stones and "Cut Me Some Slack" by McCartney with surviving members of grunge icons Nirvana.
The Grammys show, at the Staples Center in downtown Los Angeles, will climax with a rock supergroup featuring Nine Inch Nails, Queens of the Stone Age, Foo Fighters frontman Dave Grohl and Fleetwood Mac's Lindsey Buckingham.