George Gallacher

George Gallacher, who has died aged 68 from heart failure, was known best as vocalist of The Poets, the first Scottish group to make it into the Top 20.

Sharing management with The Rolling Stones, The Poets hit the charts in October 1964 with Now We're Thru, which introduced the band's unique sound, a chiming, mournful mix of 12-string guitars and plaintive vocals. Great things were expected, most of all in Glasgow, where the band's residency at the Flamingo Ballroom had built it a fanatical following. Despite a string of singles considered now as Mod and psychedelic classics, that promise was to wither on the vine, a victim of pop fashion and the band's inability to temper its instinctive Glaswegian stridency.

But the decline did not trouble Gallacher, pictured far right. A transfixing blues vocalist of the highest order, he had never found pop particularly to his taste, preferring the raw authenticity of Howlin' Wolf and John Lee Hooker. This love of the music of the downtrodden and the disenfranchised remained – alongside his family, his politics and Partick Thistle – at the heart of a life that was singularly selfless and principled.

He was raised in Dennistoun, just as American popular music was reaching its zenith. But other influences were equally powerful: an inherited regard for the principles of socialism and a love of football. Prodigiously gifted, he signed on as a youth player for Leicester City, aged 17. The solidarity of schoolmates won out and he became vocalist of a beat group, formed with his friends Hume Paton, Tony Myles, John Dawson and Alan Weir. They named themselves The Poets and – in an era when groups embraced gimmicks – created an appropriate look; vaguely Edwardian, with matching velvet jackets and tight trousers, and ruffled shirts intended to evoke Burns.

The band were sporting this costume when, in 1964, they appeared in Beat News, a publication covering the Scottish music scene. It caught the eye of Andrew Loog Oldham, the mercurial manager of The Rolling Stones, who was passing through Edinburgh Airport on his way to get married in Gretna. He saw the magazine, secured the singer's address and made for Glasgow, where Gallacher lived. "It was a Sunday morning," Gallacher would recount: "I was still in bed and my mother came in and said, 'George, were you expecting the manager of The Rolling Stones?'"

Despite a session teaching songwriting to Keith Richards, Gallacher was too wary and conscientious to feel comfortable amid the hothouse flowers of swinging London. Estrangement deepened when Oldham withdrew from band management. The disheartened Poets regrouped but without Gallacher, who would marry Anne in 1967 and take up employment as a turner at Macdonald Pneumatic Tools in East Kilbride. Ironically, he was to work alongside the father of Jack Bruce, former Cream bassist.

Football and socialism returned to him. At the plant he became a shop steward for Militant and threw himself into the junior game, turning out for Maryhill, Pollok and Saltcoats Victoria. Again, his skills were sufficient to earn him an appraisal from Jock Stein but, in his late 20s, age worked against him. With Fraser Watson, his brother-in-law and beat group contemporary, Gallacher went on to form The Dead Loss Band, whose heavier rock sound framed lyrics exploring the politics of the far left. For fun the pair played in The Dansettes, The Blues Poets and The Nearly Men, a soubriquet that emphasised Gallacher's wry attitude to his brush with pop stardom.

"I felt like I was almost married to the guy," says Fraser Watson. "People thought George was a bit of a tough cookie. It's true he never suffered fools gladly. But he had a really soft centre. He wanted to find out if you meant what you said."

Gallacher was obliged to rethink his life a second time when in 1980 he was made redundant. He opted for teaching, completing an English and philosophy degree at the University of Strathclyde, and teacher training in five years. Qualifying at the age of 49, he worked at Hyndland and Hillhead secondaries. He cherished his time at St Roch's in Townhead, where he was at the centre of a unit dedicated to teaching asylum seekers, many of whom remained his firm friends.

As they had done for four decades, Gallacher and Watson continued to play around the city, with their superior interpretations of the work of Bob Dylan, Bob Marley and Van Morrison. The Poets attempted a brief reunion last year, playing in Glasgow and London, though, typically principled, Gallacher felt uneasy singing about teenage love as he neared his 70s.

Their handful of shows were triumphant and some small compensation for the misfires of the 1960s. A life-long Old Firm refusenik, Gallacher was a passionate Parick Thistle supporter. Happily, on Saturday, he saw his team go to the top of the SFL, before suffering heart failure on his journey home: "My dad was many things," says his son Fraser, "but above all he was a humanitarian, a mentor and someone who was tirelessly decent."

He is survived by his wife Anne and sons Craig and Fraser. The funeral is at 10am on Saturday at Linn Crematorium, Glasgow.