Derek Bailey was an English avant-garde guitarist and an important figure in the free improvisation movement. Bailey abandoned conventional performance techniques found in jazz, exploring atonality, noise, and whatever unusual sounds he could produce with the guitar. Much of his work was released on his own label Incus Records. In addition to solo work, Bailey collaborated frequently with other musicians and recorded with collectives such as Spontaneous Music Ensemble and Company.

The Spontaneous Music Ensemble (SME) was a loose collection of free improvising musicians, convened in 1965 by the now late South London-based jazz drummer/trumpeter John Stevens and alto and soprano saxophonist Trevor Watts. SME performances and recordings could range from Stevens–Watts duos to gatherings of more than a dozen players.