Complex sentence: Mel Lewis, co-leader, produced a drum style with the band that was unique for big bands; the extent in which he was able to incorporate the loose, open approach of small group playing was a major innovation.
Split into simpler sentences: Mel Lewis, co-leader, produced a drum style with the band that was unique for big bands. The extent in which he was able to incorporate the loose, open approach of small group playing was a major innovation.