The Rock Hall’s 25th anniversary concert series consisted of two shows.
The event was designed as a two-day celebration and took place on October 29 and 30, 2009, at Madison Square Garden in New York City. Each night featured a large-scale succession of performances by Rock and Roll Hall of Fame inductees and other major artists, making “two” the precise answer rather than a reference to the number of acts or musical segments.
The concerts were organized around collaborative sets rather than a single headlining performance. Artists performed their own songs as well as songs associated with other Hall of Fame members. The participants included Bruce Springsteen, Aretha Franklin, Stevie Wonder, Metallica, U2, Simon & Garfunkel, Crosby, Stills & Nash, and Jeff Beck.
The series was later edited into an HBO broadcast and released in home-video and audio formats. That expanded presentation can make the event feel like a much larger run, but the live anniversary series itself was two shows.