Def Leppard photo by Gitte Meldgaard More than 30 years after they first set fire to the music world, Def Leppard continues to ignite crowds at shows across the world. The veteran U.K. rockers are currently traveling the country on the “Rock of Ages” tour, a string of dates that pulls its name from one of their many hit songs, which would later provide a title to the popular movie and musical. Vivian Campbell, who has played guitar for Def Leppard since 1992, talked to me recently about the band’s continued popularity and the current state of the music industry.