Because, all CSI (Crime Scene Investigation) theme songs were sung by the band The Who. Most probably, Anthony E. Zuiker, the show’s creator, is a big fan. The Who is a popular English band in the 1960’s-1970’s. They are also considered as one of the greatest live bands ever – because of their intense performances. They also probably pioneered the “smashing the instruments” at the end of their shows, throwing away the bits and pieces to the audience. The most popular members of The Who are Pete Townshend and the deceased Keith Moon.
Check out my individual entries for each CSI’s theme song: