Most children of rock stars grow up studiously indifferent to their parents' music, but Nat Spencer remembers in glorious detail the first time he heard his dad, Jeremy Spencer, play guitar for Fleetwood Mac.
"I had grown up in religious communes, where pop music was banned," Nat says. "And then, when I was 17, I found myself on a bus listening to a compilation tape I'd got free with a magazine. I really liked one of the tracks, so I flipped open the box and saw it was by Fleetwood Mac. I thought, so that's what they sound like."
Following in his father's footsteps, Nat, now 32, has formed a band with two of his siblings, who were also brought up in religious communes around the world.
"Koa was born in New York and has the most English accent," says Nat, pointing across the smoke-filled room to his older brother, who is 33, is dressed in an army jacket and has a shaved head.
"Our half-sister Tally" — he indicates a 25-year-old woman with short black hair and a badger-streak of blonde who is slouched on a sofa — "was born in Greece and she speaks fluent Italian. Those are the three of us who are in the band, but there are eight children altogether."
The children's story began in 1971 when their father, the blues guitarist Jeremy Spencer, was reported missing while on a tour of the United States with Fleetwood Mac. Friends said Spencer had left his Los Angeles hotel to go to a bookshop and had mysteriously failed to return.
The FBI as well as the highway and state police mounted a huge search. Appeals went out on radio and television. And then, five days later, Jeremy turned up with a shorn head and announced he had joined a religious cult called the Children of God.
As the group's road manager, perhaps used to encountering a rather different sort of trouble with rock stars away from home, remarked at the time: "He just kept mumbling: 'Jesus loves you'. It was awful, like he'd gone off his head or something. He's bloody well brainwashed, that's what."
Brainwashed or not, there was no going back. From that moment, Spencer exchanged a rock 'n' roll life with one of the biggest bands of the Sixties for one of poverty and religious duty.
Fortunately, for a rock star retiring early, there was no need for celibacy as the cult is renowned for the promiscuity of its members.
Amid general astonishment, Spencer even persuaded his wife Fiona to fly out with their two children so the whole family could become part of the sect, travelling the world and living under a strict regime in communes in Sri Lanka, India, the Philippines, Siberia, Italy and Brazil.
The Spencers increased their brood — which included Koa and Nat — to five and Fiona later went on to have three more daughters, including Tally, with a new partner.
All eight children grew up under the strict regime of the communes in which the Children of God — or The Family, as the cult now calls itself — live.
All have now left the sect, although their parents are still going strong: Jeremy lives in Ireland and phones sporadically ("Though I don't think he likes it much there," says one of his sons. "It's too wet. I think he'd like to go back to Brazil.") and Fiona is still in Italy.
Koa, Nat and Tally have now got together to form a band, Jynxt, whose latest single Bring Back Tomorrow is released this week. Their video was recently listed as the most downloaded on the internet and they are gathering good reviews and a passionate following through the gigs they play up and down the country.
Their upbeat sound is described as electronic rock and there seems to be little sign of any church influence from their cult days.
"You have to understand that the music we knew, as religious as it may have been, was very childish," says Tally patiently. "Simple tunes, hand-clapping — that sort of thing."
Hemmed in by the high walls of the communes, there were precious few other influences.
"We might have travelled a lot, but we hardly saw anything of whatever country we were in," says Nat.
"It was very harsh. We couldn't leave the commune unless we were accompanied by an older person. We weren't allowed to speak to our neighbours. Everything was screened so we had very little input from the outside world.
"If you were caught, say, listening to Guns N' Roses, you would really have been in trouble. There would have been prayers to cleanse you of all evil."
Fleetwood Mac's music was among the many things that were banned.
"Until I was grown-up, all I had heard of my dad's band was a two-second snatch on a video we were given to watch to show us how evil the real world was," says Koa.
"It showed Fleetwood Mac playing live and I remember sneaking downstairs and recording those few bars. I didn't hear the rest of the song until I was grown-up and had left the cult."
Such strict rules, however, did not extend to sexual conduct — the sect's theory was that love and sexual love were God-given, not man-made, and that it was good to share.
At one point in The Family's history, followers would try to convert the opposite sex by a process known as 'flirty fishing' — offering sex, flattery and affection to hook in new recruits.
In 1981, stories appeared in tabloid newspapers saying an interior designer called Rita Robinson had been seduced by a "handsome male Hooker for Jesus" — Jeremy Spencer. "I remember Rita. She was well fit," says Nat. "She took us all for a picnic once. Mum didn't like her much. I wonder why." He laughs.
"Koa dived into a river and cracked his skull on a rock while Rita was looking after us. That went down really well…"
Did the promiscuity impinge on them as children?
"Not really," says Koa. "We were young and besides I think it is always exaggerated. But yes, they did have group sex."
His brother Nat adds: "I think the free love thing has died down a bit since the Flower Power days. They're all getting a bit old for it now."
The siblings did not spend their time together because The Family segregated children by age, sending them to different communes within the same country.
A typical day would begin with singing, hand-clapping and prayers. Next, the children would go to religious-based lessons, followed by lunch in a big dining room. The Family ate healthily — lentils, beans, oats and wholewheat pasta were favourite ingredients.
Then came JJT — Jesus Job Time — which meant cleaning and chores. Next on the agenda was Get Out — the cult's name for PE — when the children were taken to a park to play non-competitive games.
Sometimes they would form big singing groups and go out to perform in local orphanages, or sell religious tapes and books to shops, ostensibly to act as missionaries, but also because this was the cult's only source of revenue. In the evening there was dinner, followed by an activity.
"Friday night was video night," says Nat. "We were only allowed things the upper-crust leadership had passed. Anything with a good moral — Jesus Of Nazareth, or The Sound Of Music."
Koa, Nat and Tally were also dressed in a manner terrifyingly reminiscent of The Sound Of Music's von Trapp family. Generally, clothing arrived in a huge charity bundle and everyone in the commune would rummage through the pile to find something that fitted.
But their mother Fiona also had an old-fashioned, pedal-powered sewing machine and loved to run up outfits for her brood.
She once dressed them in matching turquoise satin dresses and trousers with lavish sashes round the waist that she had made from a pair of old curtains. "We looked like Turkish flame throwers," says Koa.
Like all teenagers, they had rebellious moments. Nat remembers stealing tobacco while he was in the Philippines and rolling cigarettes using pages torn out of a copy of the Bible.
"The paper in Bibles is very thin, just like the Rizla papers you buy in newsagents.'"
Did they question their parents' religious beliefs?
"Oh yes, of course," they say.
And argue with them?
"All the time," says Koa. "Or at least, not always with our parents because as we got older they didn't live in the same commune as we did.
"You might argue with the adults in charge, but you didn't really get anywhere and you'd get a very stern rebuke and basically be put in a room for two days to fast and get your soul right with God again."
Tally says she found the begging most difficult.
"We'd have to ask the poorest people on the face of the earth for food," she says. "I remember during the two summers we spent in Siberia going to the market and people dressed in rags selling vegetables from wheelbarrows were giving us something to eat." She shakes her head.
One by one, as they came of age, each chose to leave The Family. But finding their feet in the real world was not easy.
"Getting on a bus was a new experience," says Koa. "I left with £150 and somehow managed to get to England, where I slept on my older brother's floor.
"I didn't have a national insurance number. My passport was full of strange stamps. I couldn't sign on the dole or open a bank account. I spent days wandering round shopping malls."
Then there was the fact that their awareness of popular culture — football, music, film, television — only began the day they left the cult.
During their time in the communes, the only book they were allowed was the Bible, which meant, as Nat puts it, 'we could get on really well with Christians and fanatics.
"I remember when I was first out and some latter-day saint guy came and knocked on my door to try to tell me about the Bible. He was quoting Revelations at me and I was like: 'Dude, I'm well ahead of you here'"
Tally, who has a powerful singing voice, earned money by singing in Italian clubs when she first left. Nat worked, and still does, as a freelance graphic designer. And all three are now determined to make it together as musicians.
There is only one track on their new album that is influenced by their time with the Children of God. Written by Koa, it contains the words: 'I don't believe in God.'
It caused ructions with their father, who played guitar for one of the songs on the album. He wrote to say: "If you have a song saying there is no God, I cannot and will not endorse the CD. I don't know if I need to go into more details than that except that the philosophy goes against my very grain."
But Koa refused to change the lyrics. "For me, lyrics are not some silly little off-the-cuff remarks. They actually mean something to me."
Despite such stand-offs, the children's relationships with their father is clearly very affectionate. And, perhaps surprisingly, Jeremy Spencer's children say they would never ask him to leave the cult.
"What would he do? He's nearly 60 now. He wouldn't want to tour. Besides, we can see the lure. He's out of the rat race. The communes aren't plugged into the real world. There is a certain appeal to that — even if it's not for us."