Complex sentence: Abbey started playing traditional jazz gigs in the early 1960s, typically piano/bass/drum or saxophone/organ/drum trios, which exposed him to a variety of musicians that subtly influenced his style.
Split into simpler sentences: Abbey started playing traditional jazz gigs in the early 1960s-typically piano/bass/drum or saxophone/organ/drum trios-that developed his jazz style. These early gigs exposed him to a variety of musicians that subtly influenced his style.