In non-jazz genres? And I mean people who broke through after 30 and not before! What I could think of: Tico Torres of Bon Jovi... was 33-34 when the breakthrough "Slippery When Wet" came out. Moby maybe? Wasn't he in the mid-thirties when he sold them millions of records? Andy Summers was in his thirties when he joined The Police. Rick Springfield was 32? when he started getting airplay...??? ANY OTHERS?