The official version is that they met when they were all hired by Nasa.
But why, you might ask, would Nasa want to hire musicians who turned out to be useless astronauts, especially musicians whose songs include such classics as Attack of the Manic Librarian, Rage Against the Washing Machine and a eulogy to Earl the Squirrel?
A slew of other songs that concern life on the planet Eggplantis might suggest that Kenny Young and the Eggplants are indeed space cadets or even immature. The truth, however, is that these Fringe regulars and Herald Angel winners from Brooklyn wouldn't take offence at accusations of immaturity, and that they're having far too much fun to stop. They may even have found the secret of eternal youth; Young by name and young by nature, as Mr Young has it.
"We never set out to be teen idols," says Young down the line from New York. "And some might say that's just as well. But our first thought was that if we could entertain ourselves we might entertain other people and we just kind of stumbled into this thing that we do that we all enjoy."
Heaven help the compilers of pop features along the lines of those that divulged the Beatles' favourite food and sundry minutiae had Young and his Eggplants ever come close to superstardom. He's not a man who feels comfortable giving straight responses to straight questions but he will concede that at a certain point in his youth he was invited to sing with a band at a party and enjoyed the experience so much that he decided that he needed to be involved in music.
"I also decided that I needed to learn to play the guitar because I pretty quickly realised that I was never going to be able to hear myself if I was playing with a bunch of teenage guitarists whose idea of volume control was to turn it up," he says. "So I got a guitar and as soon as I started playing I thought, this is what I want to do. I wouldn't have known who was playing guitar on any given record because they didn't announce such things on the radio.
"But later I discovered that the guy playing the really cool stuff on Elvis's records was Scotty Moore and that Stax records had Steve Cropper and I gravitated to people who could find exactly the right guitar part for a song without drawing attention to themselves. People like Curtis Mayfield, George Harrison, Dave Davies - they were all great at that."
Young could go on at considerable length about his guitar heroes - Carlos Santana, Jeff Beck , Brian May, Chuck Berry, Charlie Christian and Johnny Ramone provide a random sample - but guitar heroism, like pop stardom, was never in his plans. Meeting percussionist Eddie Logue and bassist Gil Shuster was the beginning of a long friendship that has seen the trio play at an impressive array of prestigious venues including the Royal Festival Hall and Ronnie Scott's in London and BB King's in New York as well as returning to the Fringe with, this year, promises of playing a set of theme tunes from their TV work in a parallel universe. Young began writing character songs, although not exclusively, as soon as he put his first set of lyrics to a melody and chord sequence and as soon as Logue and Shuster heard his offbeat creations, they got the zany humour and agreed that was the way to go.
"There have been times, Young says, where he's "crossed the line". A song about rats in the New York subway system got the thumbs down from the Eggplants and Young says that, looking back, they've always been right to censor him because he's recycled the basic ideas into something more suitable.
"We have been told that if we could be normal we'd be more successful," he says. "But we've always disregarded that advice. It's not that we don't appreciate being able to play big theatres and I've had moments when I've thought, this is really cool, I should remember what this feels like. But we rather like that our audiences can be children or pensioners - or both - or somewhere in between, and we know that love songs to aliens are not going to be to everyone's taste. It's our job, though, to win people over or perplex them, hopefully the former."
And what was it about eggplants that made them become such an obsession?
"Well, firstly it's a fun word," says Young. "But we also like the idea that in the vegetable kingdom the eggplant would be the rebel."
Kenny Young and the Eggplants play the Acoustic Music Centre @ St Bride's from Thursday August 21 to Sunday August 24.