John William Stevens (10 June 1940[1] – 13 September 1994)[2] was an English drummer, and a founding member of the Spontaneous Music Ensemble.

He studied at the Ealing Art College and then started work in a design studio, but left at 19 to join the Royal Air Force.

[1] He studied the drums at the Royal Air Force School of Music in Uxbridge,[1] and while there met Trevor Watts and Paul Rutherford, two musicians who became close collaborators.

Stevens played alongside a large number of prominent free improvisors in the SME, including Derek Bailey, Peter Kowald, Julie Tippetts and Robert Calvert, but from the mid-1970s, the make-up of the SME began to settle down to a regular group of Stevens, Nigel Coombes on violin, and Roger Smith on guitar.

During the mid-1970s Stevens played regularly with guitarist and songwriter John Martyn as part of a trio that included bassist Danny Thompson.