Even as Tommy cranks up in the West End in all its embarrassing frippery, even as Townshend's words about dying before he grows old are used to mock him in a poster campaign advertising, of all things, a life insurance company, even as Roger Daltrey prepares to play Judas in a Radio 2 version of Jesus Christ Superstar, nothing can shake Cast's unwavering love.
"I've never met Townshend," says John Power, the band's leader and song- writer. "But I feel I know him. He's one of the few people on this earth who said something and said it with intent."
John Power was born in 1967 ("I'm a product of the summer of love, Haight Ashbury an' all that," he says in his broad Scouse. "Oh no, hang on, my birthday's in September. All right, the winter of love"). He was thus still in nappies when Townshend unleashed the rock opera on the world in the summer of 1969. And although he was aware of songs like "Pinball Wizard" floating around in the ether, he didn't get to hear it until the conceit was well into its second decade, and the rest of the country was dancing to Spandau Ballet, Culture Club and Wham!.
"My ma's record collection was crap," he says. "And my old fella liked Eddie Cochran and Chuck Berry. He never liked the Who; he's Irish so he was suspicious of all that Union Jack nationalism stuff. He thought they were just Londoners, basically."
Power reckons it was the film of Quadrophenia that first opened his imagination. He and his mates from Quarry Bank School - the Penny Lane Gang they called themselves, because that's where they came from - took time off from wandering the very corridors John Lennon had walked to rent the film on video.
"I saw the film before I heard the album. What a film, man. Fighting, sex and great music: it's all a lad going through puberty wants. After that, this gang of us, there were about 15 lads, started listening to music - Hendrix, the Stones, psychedelic Beatles - and getting stoned. It was discovery about music, spliffs, self, everything. I remember exactly the first time I heard Tommy. Man, it kicked right in; when you're 16 you think you can put the whole world back on course when you're equipped with stuff like that."
The odd thing about the development of Tommy has been that it is the flaws that have come to symbolise the whole. At the time of writing the piece, Townshend was undergoing the most fundamental of spiritual journeys, moving towards the teaching of Baba Mehtu, the Indian mystic whose proselytising efforts were somewhat stymied by the manner in which he swore a vow of silence and didn't speak for the last 47 years of his life. Taking fragments of songs and ideas he had been working on for some time, Townshend came up with the deaf, dumb and blind kid as his unifying metaphor. It is pretty crude stuff - the way the Acid Queen fails to awaken the boy's potential symbolises the pointlessness of psychedelic drugs, for instance - often held together by dire moments of comedy ("Uncle Ernie" fiddling about). But the thread that permeates it and makes it a great piece is the creative tension of Townshend, as best realised in that first mad burst of "Pinball Wizard", up there at the top of rock's top 10 song openings.
"I don't think Townshend knew what he had or where he was heading," says Power. "I guess it's like us. It's ambiguous. When people ask me what a song's about, I'm not sure, but I know we're on the threshold of something." And yet, Power agrees, that force within Tommy has been diluted by the crass vaudeville first initiated by Ken Russell in his alarmingly bad movie.
"Oh aye, course, I'd rather sit down with the album," says Power. "I'm not arsed by the opera side of it. I'm very much arsed by the lyrics, the rhythms, the dynamics of the score. And that only kicks in when you listen to the original. What makes it is Townshend's guitar. I mean, anyone who seriously thinks they want to play guitar has to listen to Townshend, listen to the guy who carved out a path for you to follow. And Moonie's drums, that unbelievable rhythm. And Daltrey singing high with strength - that's hard, man. And the way Entwistle held the bass notes so it was like he was playing the rhythm guitar and when Townshend was playing chords, he'd fill in as lead. Christ, man, there's only three instruments in there. I mean none of that's in this chicken-and-chips cabaret show. But my ma would have a great night out there, so there's a place for it. I mean, she's not a one for listening to the album on the stereo at home, with the volume turned up to 10 and a spliff in her teeth."
But why does a young man of such creative energy bother with the output of a bunch of old has-beens.
"It's like a schoolkid's first crush," he says. "Some old bastard might say: 'We did that when we was kids, you're not doing anything new.' But the kid's head's spinning, his heart's flapping, he can't get his breath. It's new to him. It seems to me we're all working with the same thing, trying to make sense of what you're doing here, what you might call the Source. It wasn't just the Sixties, they were trying to do the same thing in the Forties. I mean Townshend, he drew inspiration from the R&B guys and the bluesmen. People have been trying to deal with this for 2,000 years, man. Way I see it, it's the same pack of cards, but each generation deals it in a different way. It's all about passing it on. The feeling Tommy evokes is unselfish. It's inspiring lads like us to know that someone like Townshend, he's just an ordinary geezer like me, but, man, he can do that."
So how would Power feel should Townshend, now a hard-of-hearing book editor with a grumpy manner and a large royalty cheque, contact him and say he really likes Cast's splendid new single "Walkaway"?
"It wouldn't change my opinion of us or our music," he says. "But course, if he liked it, it would be cool. Man, course it would."
n 'Tommy' is at the Shaftesbury Theatre, London WC2 (0171-379 5399)