42 is not the only answer!!!

In the summer of 1964 ,3 teenage friends formed the band "The Noble Five", which then changed in 1965 to "My Backyard". Their early influences included British Invasion bands such as Free, The Yardbirds, The Rolling Stones, and The Beatles, as well as Southern blues and country & western music. In 1970, the lead singer of the band sought a new name. "One Percent" and "The Noble Five" were each considered before the group settled on 'X', a mocking tribute to a physical-education teacher at Robert E. Lee High School, ___________, who was notorious for strictly enforcing the school's policy against boys having long hair. In 2004, Rolling Stone magazine ranked 'X' #95 on their list of the 100 Greatest Artists of All Time. On March 13, 2006, 'X' was inducted into the Rock and Roll Hall of Fame at the 21st annual induction ceremony.

Identify 'X'.....