Complex sentence: Confined to a wheelchair for some time, then walking with aid of a cane, the illness effectively ended his ability to work as a traveling musician again with Goodman or other bands, and prompted Powell to devote himself to music composition rather than performance.
Split into simpler sentences: Confined to a wheelchair for some time, then walking with aid of a cane, the illness effectively ended his ability to work as a traveling musician again with Goodman or other bands. It was a career and life-changing event, prompting Powell to devote himself to music composition rather than performance.