Original sentence: Rounding out the group was renowned guitarist/vocalist Wally Bryson, formerly of power-pop hitmakers Raspberries (which featured singer Eric Carmen), and two newcomers, guitarist/vocalist  Lex Marchesi and keyboardist/vocalist Frankie Vinci
Edited sentence: Rounding out the group was world renowned guitarist/vocalist Wally Bryson, formerly of power-pop hitmakers Raspberries (which featured singer Eric Carmen), and two incredibly talented & relative newcomers, guitarist/vocalist  Lex Marchesi and keyboardist/vocalist Frankie Vinci