Now that The Beatles have signed up, who are the six biggest bands still not available on iTunes and other digital download stores? 1. AC/DC 2. Garth Brooks 3. Kid Rock 4. Bob Seger 5. Def Leppard 6. Tool AC/DC and Garth Brooks believe that iTunes is "killing" music accoding to Prefix Magazine who complied the list. "Maybe I'm just being old-fashioned, but this iTunes, God bless 'em, it's going to kill music if they're not careful," said AC/DC's Brian Williams. What other bands do you find missing from iTunes?