Cleo grew up in Southall, a tomboy with unruly hair, whose English mother and Jamaican father were constantly on the move, trying to make ends meet. Though theirs was a difficult marriage and money was short, they enriched her life with their infectious enthusiasm, fun and love of music. From an early age Cleo knew she wanted to sing, and after working as an apprentice hairdresser and milliner, in a library and pawn shop, she finally made her break when she auditioned for John Dankworth in Soho in the early 1950's.

After she and John married, Cleo forged a career on her own in a wide range of stage performances, from straight plays and satire to musicals including 'Valmouth' and 'Showboat', Kurt Weill's 'Seven Deadly Sins' and Sondhiem's 'Into the Woods' and also collaborated with John Dankworth in works such as 'Lysistrata' and jazz performances. Cleo has won a Tony Award for her Broadway performances and Grammy Awards for her jazz recordings.

Cleo and John toured the world including America and Australia at festivals including Newport and the celebrated Birdland club in New York and wayout clubs in New Orleans, meeting and collaborating with the giants of jazz Dizzy Gillespie, Count Baise, Duke Ellington, Ray Charles, Frank Sinatra, Mel Torme and Dudley Moore.