My pop idol had feet of clay

When Michael Hann saw through his hero, he began to doubt his own identity

I am a 32-year-old man, with a marriage, a mortgage and a year-old daughter. But I feel like a teenage girl: I have lost my pop hero.

Mine didn't break my heart by getting married; I just saw through him. His name is Alex Chilton and he is best known, in so far as he is known at all, as the singer of an American band called Big Star, who split up in 1975 but played one of their occasional reunion gigs the other week in London. Chilton is an authentic cult hero, hailed as one of the great songwriters by the few thousand thirtysomething and older men who care about these things, in part because he never sold more than a few records.

But Chilton, I now realise, is a man who has an unpleasant fixation with the sexuality of young girls. Chilton has always defended his song "Thirteen", which is about being obsessed with a girl of that age, by saying it was written from the perspective of a 13-year-old boy. So why, at a gig in 1993, did he choose to dedicate it to Michael Jackson? Was he also adopting a child's perspective the other week when he sang a song called "Patti Girl", whose subject is "only 12 years old", and another called "Hot Thing", about a girl who's "too young to go steady"? And what was he up to when he recently released a solo album called Loose Shoes and Tight Pussy?

At the gig, the young men in front of me sniggered, then quoted the words of the songs back to each other as if they were the highlights of a stand-up comedian's set. A few years ago, I would have reacted in the same way. But now I am a parent, and if my child had been a boy, I might well have named him Chilton. What kind of deluded fool had I been?

I've loved pop - really loved it, the way the characters of Nick Hornby's High Fidelity do - since my teens. I take it far too seriously; my wife has accused me of being more interested in the history of the Creation record label than in her or my daughter.

Why, as a responsible adult, do I attach such importance to pop singers? And why do I feel so cheated when I am robbed of my faith in them? It has to be a male thing. I don't know a single woman of my age who still believes Duran Duran are prophets without honour, or that Spandau Ballet are among the great underrated artists of the late 20th century. But I know plenty of men who will sit for hours arguing about the relative importance of the Beach Boys and the Byrds, assertion heaped upon assertion.

There are swathes of men who need heroes well into adulthood; it is part of the way we order the world. We like to assess and rank the forces that we feel have shaped us. Unless we can assign a precise value to something, we cannot be sure how greatly it has affected our lives. Some do that with politics, others with sport. I do it with pop music, because that is what has defined my life through its most crucial moments. I remember relationships, new jobs, exam results through the records I was listening to at the time; for example, my daughter was born to "Hang on to Your Ego" by the Beach Boys (although I had hoped she would emerge to "God Only Knows", the song with which I wooed my wife).

Women claim men obsess about pop and sport because they provide substitutes for conversation. Wrong. Every chat about music and football is a sophisticated code that enables men to assess each other's personality, background, aspirations, professional status and world-view. Sometimes the assessments might even be accurate.

So our heroes are not embodiments of virtue, but those with whom we have stayed for the long haul, those in whom we have invested the most time and effort. By virtue purely of their (or, more accurately, our) constancy, they have provided the framework for our lives.

But when our relationships with our heroes collapse, we realise that the ordering of our lives was founded on cultural sand. If I could have been so wrong about Alex Chilton, what else might I have been wrong about? And if he is not who I thought he was, am I the person I thought I was? Laugh as much as you like, but I bet I feel the same as the Gang of Four did when they left the Labour Party to found the SDP.

Asked if I liked Big Star, my "yes" really meant something like: "My attitudes and outlooks are shaped by the 1960s, though they are not of that decade. I enjoy being a step more esoteric in my tastes than most people, though I am not so adventurous as to be interested in experimentalism. I take popular culture seriously, and am willing to spend a great deal of time researching the subject. I went to university, I am left-leaning but I love Americana." Now I have to say "no" and it will mean: "I fear I am at one with the News of the World."