ALEX ST CLAIR was responsible for bringing the voice of Captain Beefheart to the world.

In early 1965 St Clair invited him to sing with his band at a Californian college. Beefheart, who had never performed in public, went on to become one of the most extraordinary and influential figures in alternative rock.

As the leader of the first line-up of his Magic Band, St Clair played a key role in helping to forge the radical sound on such seminal Captain Beefheart albums as Safe as Milk and Strictly Personal.

Born Alexis Clair Snouffer in 1941, he grew up in Lancaster, a satellite town of Los Angeles about 80 miles from the city. At school his fellow pupils included Frank Zappa, leader of the Mothers of Invention, and Don Vliet, the future Captain Beefheart.

While St Clair and Zappa both played in the high school band, Vliet was a more retiring musician, concentrating on painting, although he did add some vocals to early recordings with Zappa and St Clair.

In 1964 St Clair left town to take a job at a casino in Lake Tahoe but on his return to Lancaster, he put a group together to play R&B covers, with the guitarist Doug Moon, the bassist Jerry Handley and the drummer Paul Blakely. He also asked Vliet to sing with them at their first gig, a “battle of the bands” contest at Pomona College, Claremont, California.

“I don’t think we knew how to play together but we knew we had sufficient music in us to beat the other group,” St Clair recalled.

According to Beefheart’s own account, he told St Clair: “I never sang anything. I don’t know anything about music.” St Clair said: “Tonight you’re going to sing.” St Clair then told Vliet his voice was undeniably “horrible”, but if they played the gig, it could only get better.

St Clair also played a key part in the strange names that became part of the Beefheart legend. When he decided to rename himself Alex St Clair, Vliet followed suit, adding Van as a middle name. “We changed our names because the police were after us for smuggling sponges into Nevada,” St Clair claimed in a typical example of the zany humour of the time.

Soon the group was known by the even more exotic appellation Captain Beefheart and His Magic Band, and Vliet gave all of his musicians pseudonyms of studied weirdness.

The band’s new name betrayed the shifting balance of power between the two men. Initially Magic Band had operated as a collective, with Beefheart contributing lyrics and St Clair taking the lead musically. But Beefheart swiftly emerged as the dominant and ultimately dictatorial personality, shaping the band to reflect his own musical vision and his growing confidence as a writer and singer.

By 1966 the group had secured a recording contract and cut their debut single, a version of Bo Diddley’s Do Wah Diddy, improbably produced by David Gates, who went on to fame with the middle of the road soft-rock group, Bread. The single attracted the support of John Peel, then working as a disc jockey in California and who became the band’s most ardent fan. But after a second single, A&M dropped the Magic Band.

With the addition of Ry Cooder on slide guitar, they then signed to Buddah and in 1967 rerecorded the material A&M had rejected. The result was Safe as Milk, a remarkable record that marked the first flowering of Beefheart’s warped blues sound, but was also characterised by St Clair’s impressive, staccato guitar playing.

He stayed for a second album, Strictly Personal in 1968, but after a European tour St Clair left the band, to be replaced by Bill Harkleroad (also known as Zoot Horn Rollo).

By then St Clair was married, and — uncomfortable with what he saw as Beefheart’s rapidly expanding ego — was also looking for greater financial security. This meant he did not appear on Trout Mask Replica in 1969, one of the great cult albums, although given the stories of what Beefheart put his musicians through during its recording, he may well have regarded this as a blessing.

Yet he remained on friendly terms with Beefheart and after some old sessions featuring St Clair had been belatedly issued on the album Mirror Man in 1971, the following year he rejoined the line-up.

An apparently contrite Beefheart apologised in an interview for his past attempts to “sculpt” his musicians in his own image. Yet the rapprochement did not last long. After playing on the Unconditionally Guaranteed album, St Clair left again in 1974 after a confrontation with Beefheart over money that resulted in the entire Magic Band leaving.

Beefheart did reach out one last time, when Vliet recorded the song Owed T’Alex on the 1978 album Shiny Beast (Bat Chain Puller), with lyrics that recalled St Clair’s visits on a motorbike to see his mother in Carson City in the 1960s.

Beefheart gave up music in the early 1980s to return to his first passion of painting, and St Clair was never to play in a successful band again.

In later life he worked as a gardener and a barman and he also spent time in a rehabilitation facility. He was found dead in his apartment in Lancaster, California.

Alex St Clair, guitarist, was born on September 14, 1941. He died on January 5, 2006, aged 64.