Complex sentence: This aided his musical development considerably, as did his membership, in 1953, of Teddy Charles' New Directions band--the compositions he encountered in this band allowed him to consider a broader range of expression during improvisation.
Split into simpler sentences: This aided his musical development considerably, as did his 1953 membership of Teddy Charles' New Directions band. The compositions he encountered in this band allowed him to consider a broader range of expression during improvisation.