Complex sentence: Jazz saxophonist Stan Getz who had heard her sing "Amazing Grace" at Monterey in 1979, did not give up on her and was a behind-the-scenes mover who arranged a second appearance for her at the Monterey Jazz Festival three years later.
Split into simpler sentences: Jazz saxophonist Stan Getz who had heard her sing "Amazing Grace" at Monterey in 1979, did not give up on her. Getz was a behind-the-scenes mover who arranged a second appearance for her at the Monterey Jazz Festival three years later.