I've been thinking about artists who go through many changes at the beginning of their careers but settle into groove they like for the last half of their life that may seem less adventurous than what they were doing at the beginning: Miles, Dylan, Sonny, Dizzy-- anyone got any other examples? Who knows what Coltrane would have done in the last twenty years he should have had.
And I think I saw Sonny in every decade since the '60s. The only time I was disappointed was in '64 or '65 when it seemed to me he was too influenced/intimidated by Coltrane. IIRC he was accompanied by Grant Green! (Did I hallucinate that?)