Complex sentence: Jolliffe has been an active keyboardist, flutist and saxophonist since 1967, when he met Rick Davies and formed a group called The Joint, which, after Steve left, evolved into Supertramp.
Split into simpler sentences: Jolliffe has been an active keyboardist, flutist and saxophonist for over 35 years. His career started in 1967, when he met Rick Davies and formed a group called The Joint, which, after Steve left, evolved into Supertramp.