John Gustafson, who memorably collaborated in the '70s with Ian Gillan and Roxy Music, has died at 72. He had once been deemed the "second most important bassist ever to come out of Liverpool" for his work in the groundbreaking early-'60s power trio the Big Three. Gustafson was also part of the well-received prog group Quatermass.

Bernie Torme, a late-period member of Quatermass, confirmed his death via Facebook. “RIP to the great John Gustafson, who did so much for music from the Big Three onwards," Torme said. "A true one off.”

The Big Three was actually signed by Beatles manager Brian Epstein, reportedly on John Lennon's recommendation. "I can’t recall another rock trio at that time in Liverpool, although I can’t be sure," Gustafson once told DMME. "We got away with it at first by being loud and aggressive, until we developed a trio playing style. Whether or not we influenced any other trios is open to debate.”

Like the Beatles, they had an early '60s trial with Decca, and released a pair of UK Top 40 singles in 'Some Other Guy' and 'By The Way.' (The Beatles' earliest setlists also included 'Some Other Guy,' written by Leiber and Stoller.) Gustafson was subsequently a member of the Merseybeats, and performed on the original soundtrack of 'Jesus Christ Superstar' with Gillan and future Wings guitarist Henry McCullough.

Quatermass was formed in the same period, having developed from the remnants of the pre-Deep Purple band Episode Six. Gustafson appeared on the 1974 concept album 'The Butterfly Ball and the Grasshopper's Feast' with Gillan's Deep Purple bandmate Roger Glover, as well.

He'd collaborate with Roxy Music from 1973-76, a period that saw Gustafson perform on their celebrated track 'Love is the Drug.' He then joined Gillan after the singer left Purple, releasing a quartet of more jazz-oriented albums before breaking up in the late '70s. "Gillan decided he didn’t like the band’s direction and wanted to do more rock stuff," Gustafson said. "In reality, he should have put his foot down a lot earlier. I personally was expecting Deep Purple stuff, but he let us do whatever we wanted."

Gustafson released 'Goose Grease,' a lone solo album, in the mid '70s. His latter-day career included sessions work, notably with Steve Hackett, Rick Wakeman, Jerry Lee Lewis and Ian Hunter. Gustafson was also famous internationally for work with a re-formed edition of the Pirates, Johnny Kidd's old backing group.