Beck attended Clive Davis' annual pre-Grammys party in 2016 (having won album of the year in 2015). He also performed one song, singing a David Bowie song, while backed by the surviving members of Nirvana. (There was also a woman bowing a bass/cello, but unsure who that was.)
A lot of other people performed songs as well.
[people and bands
Drums: Dave Grohl
Guitar (Acoustic): Beck Hansen, Krist Novoselic, Pat Smear
Other Band: Audra Day, Barry Manilow, Carly Simon, Chicago, Earth Wind and Fire, Elle King, Fetty Wap, Jack Antonoff, Melissa Etheridge, Tori Kelly
Vocals: Beck Hansen