Their father was a blues guitarist with one of the biggest bands of the Sixties but they grew up never hearing his greatest hits.
For Jeremy Spencer dropped out of Fleetwood Mac to build a new life with the Children of God religious cult renowned for sexual promiscuity and travelling the world.
Although his children spent hours singing Christian songs, they rarely heard pop music in their communes in Britain, Sri Lanka and Brazil. But three of them - Koa, Nat and their half-sister Tally (Talitha), now all adults - have defied Spencer's wishes to follow in his footsteps with their own band, Jynxt.
Their first album, Bring Back Tomorrow, has just hit the shops and the title track will be released as a single next week. "We're waiting for our big break," said Nat.
Yet when they were growing up they could never have dreamt of their current life of recording, playing gigs and living in suburban north London.
The Children of God, also known as The Family, had strict rules which meant every day was organised. The children were segregated by age group, even to the extent of living in different countries from their siblings. They travelled as missionaries, raising funds for humanitarian projects and attempting conversions - just as their father was converted while on tour in Los Angeles in the 1970s.
The Hartlepool-born musician had left the band's hotel to go to a bookstore and was recruited by a cult member who sang him a song. Eventually his wife, Fiona, flew out to find him - and joined the sect herself. Already the parents of two children, they produced three more before Spencer moved to another commune and Fiona had a further three daughters, including Tally, with a new partner. She is still with the cult in Italy while Spencer remains a member in Ireland.
Tally, 25, said: "Obviously we weren't allowed to listen to any music so maybe that's why our music sounds a bit different from anything else we're hearing." Nat, 32, added: "As far as popular culture goes, my knowledge pretty much started in 2000." He was 17 before he heard one of his father's songs on a tape that came with a magazine. "I thought, 'Oh, that's a nice song and looked on the cover and it was Fleetwood Mac'."
Although the cult has a reputation for brainwashing, it failed to work for the eight siblings, all of whom eventually quit. Nat left later than most, at 25, because for several years he worked with his father in a studio in Brazil, producing albums of religious songs.
But eventually he joined his brothers Jez and Koa in London. He trained in web design and proudly secured a job in a "proper" company. "But it got to be quite tedious after a while, the rat race," he said. "I could understand why my parents ran from it." The brothers formed a band and, realising neither of them would cut it as singers, contacted Tally in Italy. Impressed by a CD of their songs, she flew over and Jynxt was born.
Their parents have been sent the album although they are unlikely to listen to it. "It's not very religious music. Some might say it's a little anti-religious," said Nat. Lyrics include "I don't believe in God".