The Grammys have been overshadowed by the shocking arrest of a nominee as the broadcast was taking place - teen heartthrob Chris Brown, who was in police custody for an alleged felony assault on an unidentified woman the night before.
Police records showed he was being held on US$50,000 bail.
Brown and longtime girlfriend Rihanna, also nominated, were both slated to perform in different slots of the show, but separately dropped out at the last minute.
The victim of Brown's alleged assault wasn't identified, and it wasn't immediately clear whether Rihanna's absence was related to Brown's.
Rihanna was supposed to sing "Live Your Life/Disturbia" as the second performance of the night, Brown was later to sing "Forever."
Each was nominated in the pop collaboration with vocals category, Brown for "No Air" with "American Idol" champion Jordin Sparks; and Rihanna for "If I Never See Your Face Again" with Maroon 5.
Brown was also nominated for male R&B vocal performance for "Take You Down."
Neither won a Grammy on Sunday, and the Recording Academy found able replacements for their performance slots in Justin Timberlake, Al Green, Boyz II Men and Keith Urban as they all sang Green's classic hit, "Let's Stay Together."
No mention was made on the broadcast about the switch.
According to the police report, released 90 minutes before the show began on Sunday, Brown and a woman were in a vehicle in the ritzy neighbourhood of Hancock Park when they began to argue around 12:30 a.m. on Sunday.
Brown stopped the car and both got out, whereupon the argument escalated, the report said.
The woman, who had visible injuries when police arrived, identified Brown as her attacker, but he had left the scene, the report said.
Los Angeles police officer Karen Smith says Brown walked into a station around 7 p.m. and was being interviewed by detectives.
