The band was formed at the height of the British "blues boom", with the emergence of guitarists such as Peter Green, Jeff Beck and, later, Jimi Hendrix.

It was during this period that Etheridge further developed his interest in jazz and fusion, an important influence at this time being John McLaughlin's 1969 debut album, Extrapolation.

He recalled: "I'd been on the fringes of the London rock scene for a couple of years, and one of the musicians I came across was [Icarus woodwinds player] Norrie Devine.

[2] In late 1972, Etheridge joined Curved Air violinist Darryl Way's band Wolf, which went on to record three albums in the progressive rock canon for the Deram label: Canis Lupus (1973), Saturation Point (1973), and Night Music (1974).

Following Wolf's break-up, Etheridge briefly played in the Global Village Trucking Company for a UK tour supporting Gong in early 1975, before a recommendation from fellow guitarist Allan Holdsworth led to him joining Soft Machine, now in full fusion mode having just released Bundles.

[1] The 1980s saw Etheridge remain very active on the live front – including a reunion with Soft Machine for the band's final series of concerts at Ronnie Scott's Jazz Club in 1984 – but much less productive in the studio.

In 1994, he released a duo album, Invisible Threads, with longtime friend Andy Summers (a former Soft Machine guitarist, albeit in a much earlier incarnation of the group), and did a world tour with him.

The same year, Etheridge released his first solo album, Ash, mostly featuring his regular band at the time – Steve Franklin on keyboards, Henry Thomas on bass and Mark Fletcher on drums – as well as duets with bassist Dudley Phillips.

In addition to countless one-off line-ups assembled for jazz gigs, Etheridge is involved in several long-term projects, including: a guitar duo with John Williams, which released Places Between – Live in Dublin; the Grappelli tribute Sweet Chorus, which released Sweet Chorus – Tribute to Grappelli in 1998; the Frank Zappa tribute band, Zappatistas,[4] (formed 1999), who released a live CD, The Music of Frank Zappa – Absolutely Live (2001) and have since toured widely, appearing at the German progressive rock/jazz festival Zappanale[5] in 2006; and Soft Machine Legacy, alongside fellow ex-Soft Machine members Hugh Hopper, John Marshall and Elton Dean (the latter replaced by Theo Travis after Dean died in early 2006).