A Nirvana fan wears a hoodie with an image of Kurt Cobain.

A Nirvana fan wears a hoodie with an image of Kurt Cobain. Photo: Reuters

MY FIRST was REM. It was white, loose and had a chequerboard on the front. I bought it - secretly - from the back pages of the rock music newspaper the NME; I ran for the postman every morning, before my mother did, to check if it had arrived.

The day it came, I ran upstairs, locked the door and put it on. Fifteen years old, there I was in my first band T-shirt and, just like that, I felt part of something.

The band T-shirt is one of music's most potent totems. Wear one and it points out an allegiance, however confident or timid the wearer. Six months ago, Ian Wade and I started a blog, My Band T-Shirt, to tell their stories. I began with a story about an Orbital top given to me by a boyfriend; Ian followed with a tale of living in a Blur top for a year.

A Sex Pistols T-shirt.

A Sex Pistols T-shirt.

Inviting others to post stories, we were staggered by the emotions bundled up in them: people gave birth, lived and died in the shadow of their screenprint; life's rich tapestry was revealed in these scraps of cotton.

Band T-shirts first appeared 50 or so years ago. The Beatles and the Dave Clark Five were early adopters, two bands that understood merchandising. Then came the hippy phenomenon of tie-dye with a logo slapped on top.

Johan Kugelberg, author of Vintage Rock T-Shirts, doesn't put their success down to the power of music. ''What broke band T-shirts was mass distribution, just like everything else.''

The idea of branding yourself with a musician's name wasn't new, according to Kugelberg. ''Bobby-soxers [in the 1940s] began the trend of writing the name of their favourite singer across the back of their jackets - a flourish of Frank, or a swirl of Sinatra. Band T-shirts were a later extension of that.''

By broadcasting love for an artist on their chest, Kugelberg says, a person could suggest a mystical connection between themselves and a superstar.

Band T-shirts reveal contradictory impulses in owners, a desire to be seen differently, but also to fit in. On our blog, Stevie Chick claims, tongue in cheek, that his T-shirts reveal ''exquisite taste and enviable cultural nous''; Sarah Drinkwater confesses to using her Blur Mile End Stadium T-shirt to pretend she was at the 1995 gig, when in fact she cried off at the last minute, afraid of her father's reaction if he found out she'd been.

Kugelberg thinks T-shirts are status symbols. ''They're middle-class luxury items, no doubt. It's luxury consumption. It's what brand you slap across your chest.''

This doesn't explain the hymns to self-made T-shirts that have been sent to our site - including a David Bowie logo reappropriated from a too-tight pink top, or the disastrous Sweet T-shirt made by Mark Wood (''The end result was bits of melting Sweet faces all over the place and an iron that had to be thrown away.'').

More than anything, band T-shirts are about communicating hidden messages. In hindsight, I know how much meaning I ascribed to my Oasis Shakermaker T-shirt, worn to my first day at college, bought with paper-round money. It said: ''be gone, school; be gone, uniform; be gone financial dependence; hello all you new people who might understand me.''

Dick Hebdige's 1979 sociological classic Subculture: The Meaning of Style framed these feelings in academic lingo.

''It is through the distinctive rituals of consumption, through style, that subculture at once reveals its 'secret' identity and communicates its forbidden meanings.''

That explains why band T-shirts are often embraced by alternative genres and why, after tie-dye, the rock T-shirt market was dominated by the black cotton of heavy metal. Grunge did similar business, but there was also irony, with logos of soft rock bands such as Boston worn as a sign of self-awareness. Later, this trend was adopted by the mainstream, and soon band T-shirts trickled into high street fashion. David Beckham, at the peak of his turn-of-the-century fame, was pictured wearing a T-shirt with the Crass logo picked out in diamante studs. Here, T-shirts were simply the vehicles for the communication of a vague kind of ''cool'', unrelated to the messages the original wearers had wanted to convey.

Sometimes T-shirts would become better known than the band. The Ramones probably sell a great many more T-shirts now than they did records in their heyday.

But why do we still cling on to band T-shirts as adults? It's partly nostalgia, Kugelberg says, but it goes deeper than that. ''A T-shirt can help us acknowledge the changes we've gone through in our lives. When we're approaching middle age, we want to show why we were part of something meaningful.''

Perhaps it is telling that the most touching posts on our site have been about T-shirts that were discarded. John Earls got rid of his when he moved in with his girlfriend. The boyfriend who gave me my Orbital T-shirt, which I still wear to clean the house, regretted his own T-shirt cull: ''As a public information warning, I urge you: don't throw them out.'' GUARDIAN

To contribute your own T-shirt, go to mybandtshirt.tumblr.com.