Complex sentence: He developed further at Berklee College of Music where he studied under Herb Pomeroy and Gary Burton, then served a big band apprenticeship with Woody Herman's Thundering Herd and the Mel Lewis Jazz Orchestra.
Split into simpler sentences: He developed further at Berklee College of Music where he studied under Herb Pomeroy and Gary Burton. Following this, he served a big band apprenticeship with Woody Herman's Thundering Herd and the Mel Lewis Jazz Orchestra.