Well, that escalated quickly. We're used to seeing the Foo Fighters on stage with a classic rocker or two, but last night's concert at the Forum in Los Angeles featured a veritable parade of stars. Highlight fan-shot moments from the show are embedded below.

Paul Stanley opened the show with the Foos, performing Kiss' 'Detroit Rock City' and 'Do You Love Me,' before Slash and Tenacious D joined Dave Grohl and company for 'Tie Your Mother Down' and 'Immigrant Song.' Alice Cooper was there for 'School's Out' and "I'm 18.' Zakk Wylde collaborated on 'N.I.B.' and 'Fairies Wear Boots,' both Black Sabbath classics from his old boss Ozzy Osbourne.

Perry Ferrell sang 'Miss You' and 'Mountain Song.' Toward the end of the set, David Lee Roth leaped on stage -- sporting a new shaved look -- for renditions of Van Halen's 'Panama' and 'Ain't Talking 'Bout Love.' Lemmy from Motorhead then closed things out with the Foos, performing Chuck Berry's 'Let It Rock.' A full set list has been posted by the Van Halen News Desk.

Watch David Lee Roth and Foo Fighters Perform 'Panama'

Watch Foo Fighters On Stage with Paul Stanley

Watch Foo Fighers On Stage with Alice Cooper

Watch David Lee Roth and Foo Fighters Perform 'Ain't Talking 'Bout Love'

Watch Foo Fighters Perform 'N.I.B.' with Zakk Wylde

Watch Perry Ferrell Perform 'Mountain Song' with Foo Fighters

Watch Slash and Tenacious D On Stage with Foo Fighters

Watch Lemmy Cover Chuck Berry with Foo Fighters

The occasion was Grohl's 46th birthday. Tickets for this special in-the-round performance partially benefited charities, including MusiCares, Sweet Relief and Rock School Scholarship Fund. Foo Fighters are set to kick off their largest North American tour ever later this year.

See the Yearbook Photos of David Lee Roth and Other Rock Stars