Edwards departed the band in 1977 and was replaced by drummer Cornell Marshall. Singers Winston "King" Cole, Prilly Hamilton, and Beres Hammond all fronted the band at one time or another, but Zap Pow was at heart primarily an instrumental configuration, and while its live shows were legendary, it was a crack studio session band. Zap Pow had a minor hit on Hammond's watch with "The System " in 1978 and a massive one with "This Is Reggae Music" for producer Harry J. Combined with trombonist Vin Gordon, Madden and DaCosta were frequently billed as the Zap Pow Horns, and worked with Bob Marley in that capacity for a time. The Rhino compilation called Reggae Rules, which collects singles the band released between 1973 and 1980, is a good starting point to get a sense of this exciting group, which mined a synthesis of reggae, jazz, funk, and soul well before such a concept became fully accepted. ~ Steve Leggett