The English rock band that performed CSI: Crime Scene Investigation's theme song “Who Are You” was The Who.
The song was written by The Who's guitarist and principal songwriter, Pete Townshend, and features lead vocals by Roger Daltrey. It originally appeared as the title track of the band's 1978 album Who Are You, released shortly before the death of bassist Keith Moon.
CSI adopted “Who Are You” as its opening theme when the series premiered on CBS in 2000. The title created a memorable wordplay connection with the show's investigations, which often revolve around identifying victims, suspects, and evidence. The song was not composed specifically for television; it was an established rock recording selected for the program.
A common mix-up is confusing the original band with the show's composer. John M. Keane composed CSI's score and much of its instrumental music, but The Who performed the opening theme. In some countries, alternative theme music was used because of licensing arrangements.