Maybe Def Leppard don't know their downloadable content from their full-price retail products. Few weeks back they told a radio show that three of their songs would be appearing in Guitar Hero IV. And hey, they still might, but the timing of that interview and today's announcement that three of their songs would be appearing as DLC for Guitar Hero III has me thinking they're not as up-to-speed on their roman numerals as they are on the whole rock n' roll business. On April 24 (May 8 for Europe), the Def Leppard songs Photograph and Rock of Ages will be made available as DLC, along with new single Nine Lives. This last one's interesting because the song will be debuting in the game. Not on radio, not on TV, not even as a ringtone, but as a playable track in a videogame.