At the suggestion of producer Bob Ezrin, Wagner contributed guitar tracks to the highly successful 1976 Kiss album "Destroyer" the first Kiss album to prominently feature outside musicians. Though uncredited, Wagner replaced Ace Frehley as lead guitarist for the tracks "Flaming Youth" and "Sweet Pain", while also playing the acoustic guitar found on the ballad "Beth". As one of Ezrin's hired guns throughout much of the 1970s and 1980s, Wagner continued to lend his playing (and in some cases, songwriting) talents to albums including Peter Gabriel's self-titled solo debut (1977), Air Supply, Aerosmith's "Get Your Wings" (Wagner played the guitar solos on "Same Old Song and Dance" and "Train Kept A-Rollin'", the latter with Steve Hunter), Hall & Oates' "Along the Red Ledge", Kiss's "Revenge", and Burton Cummings' "Dream of a Child". Wagner produced and co-wrote songs for Mark Farner's solo début and a pair of albums for the star of "The Rocky Horror Picture Show", Tim Curry, and more.