 Middleton worked with Beck in the Jeff Beck Group line-up with vocalist and guitarist Bobby Tench, Clive Chaman and drummer Cozy Powell.He stayed with Beck until the latter's power trio, Beck, Bogert & Appice began to emerge as an established act, before leaving to join Tench in Hummingbird during 1976.Hummingbird released two successful albums with Middleton as keyboard player "We Can't Go On Meeting Like This" (1976), and "Diamond Nights" (1977), both produced by Ian "Sammy" Samwell.