Mejla Hlavsa, who has died of cancer at the age of 49, was a legendary rock musician who did not choose the anti-regime role that was thrust upon him, but accepted it graciously and, through his music, became a figurehead in the movement which eventually overthrew communism in Czechoslovakia.
The founder, songwriter and bass guitarist of the psychedelic rock band, the Plastic People Of The Universe, he first achieved international fame when he was arrested and imprisoned - along with three other band members - in 1976, for "organised disturbance of the peace". The future Czech president Vaclav Havel was among the domestic and international intellectuals and artists who voiced their outrage, and so it was that the Plastics' trial galvanised the human rights movement Charter 77, which fuelled the velvet revolution some 22 years later.
"Vaclav was the engine of the efforts," Hlavsa told the Guardian in a 1998 interview. "The band itself had no political ambition, and we didn't intend to destroy communism through our music. If we helped, we are only too glad." The words of Epitaph, a song from the first Plastics' album, Egon Bondy's Happy Hearts Club Banned, are a poignant legacy of the gravel-voiced musician: "It's too late now to protest/ I've been laid to rest."
Hlavsa was born in Prague to a bankclerk father and a housewife mother. Coming from a generation that considered western-influenced music highly suspicious, and saw long-haired men as "hooligans", they thoroughly disapproved of their son's musical aspirations.
He first developed his passion for rock music in the early 1960s, when his brother Vaclav, nine years his senior, started bringing home rock 'n' roll recordings which had mostly been smuggled into the country. He formed his first band at the age of 14. In 1967, he heard the first Velvet Underground album; he later told friends it was "to influence the rest of my life".
He formed the Plastics a month after the Soviet-led invasion of Czechoslovakia in August 1968, which crushed the Prague Spring. The name was taken from the Frank Zappa song, Plastic People, and a quotation of Andy Warhol: "I love everything that is plastic, I would love to become plastic." The band was dismissed by the Czech communist daily, Rude Pravo, as "long-haired, neurotic drug addicts and mental cases who take delight in the grossest of perversions and deliberately sing vulgar, anti-social songs".
When the Plastics' official status was revoked, they refused to give up, playing impromptu concerts under the guise of cultural theory lectures, often in village halls and secret locations. The quietly subversive Czech spirit meant they were never short of an audience.
Their lyrics were smuggled out of Bohemia in samizdat form, their music dubbed and redubbed onto bootleg cassettes, and distributed often via diplomatic channels. Havel lent the Plastics his farmhouse at Hradecek, and offered advice on lyrics when their songwriter was arrested by the secret police.
In 1998, Hlavsa said the Plastics felt "more like a guerrilla group than a rock 'n' roll band", when, in 1974, fans, arriving in the southern town of Ceske Budejovice for a concert, were set on by police, who clubbed them before herding them onto trains back to Prague. Many were expelled from university as a result. Despite the difficulties the Plastics faced, including their arrests, trials and imprisonments in 1976, they continued to perform underground, finally splitting up in 1987.
In 1992, the now President Havel took Lou Reed, a founder member of the Velvet Underground, to a club in downtown Prague where Hlavsa was playing in the Velvet Underground Revival band. Hlavsa recalled the occasion: "Lou was really impressed. He said: 'These guys know all my songs better than I do.' I said to Lou: 'My dream's come true, now I can die.' Lou said: 'Don't do that, my friend, it would be a tragedy."'
In 1997, Havel held a Plastics' reunion concert at Prague castle to celebrate the 20th anniversary of Charter 77. It was the band's first ever official concert, in contrast to their usual rundown venues with equipment cobbled together from junk. A major tour of the Czech Republic followed, and a New York concert in the summer of 1998 was hailed with rave reviews. That September, Hlavsa performed alongside his hero, Lou Reed, at the White House, in front of the Clintons and President Havel. He had had to borrow a smart jacket for the occasion from a Prague neighbour. A new album was due to be recorded later this year.
Latterly, Hlavsa bemoaned how materialistic the new Czech society had become, but insisted his only aim was to "make music, not money or politics". He will be remembered for his modesty, kindheartedness and charm, as well as his gift for storytelling.
He is survived by his mother, his wife Jana, the daughter of the Czech writer and philosopher Jiri Nemec and Dana Nemecova, of Charter 77, and their two children.
• Milan 'Mejla' Hlavsa, rock musician, born March 6 1951; died January 5 2001