The Rock Against MS Benefit took place in Hollywood at the Whiskey A Go-Go on March 27th and featured an all-star jam session including musicians Marky Ramone, Billy Duffy, Lemmy, Steven Adler, Glenn Hughes, John 5, and Billy Morrison. Near the end of the show, Billy Idol surprised the crowd and jumped onstage for a performance of "Rebel Yell." Check out the action below: