Considering the quantity of rock star photos adorning the Sunset Marquis’ walls during normal business hours, it only made sense that the hotel’s 50th anniversary party should be a thoroughly tuneful affair.

Steven Tyler and Julian Lennon helped ring in the hotel’s semi-centennial on Nov. 16, singing beside a giant birthday cake, while Lemonhead Evan Dando and the Doors’ Robby Krieger jammed on the Rolling Stones’ “Dead Flowers” at the other end of the hotel grounds.

Two-thirds of the Jonas Brothers, Kevin Jonas and Joe Jonas, were spotted at the Charity Poker Tournament, and proceeds from the event were donated to MusiCares.

Liz Phair, Taylor Dayne and Whoopi Goldberg also circulated through the bash’s various areas, each stocked with plenty of spare acoustic guitars in case a moment of inspiration should strike.