He co-founded the progressive rock bands Freedom's Children and Abstract Truth.
Henson's first notable band was Freedom's Children, a group he formed in 1966 with bassist Ramsay Mackay and drummer Colin Pratley.
After releasing just two songs with Freedom's Children, he left the band in 1968 to join The Bats for a six-week sojourn.
[1] In 1969 he formed the group Abstract Truth with Mike Dickman and Pete Measroch.
[4] In the last two decades of his career, Henson worked with many South African musicians, including Piet Botha, Steve Fataar, Neill Solomon, Roger Lucey, Nibs van der Spuy.