What makes a No 1 nouveau-glum stadium band? Brian Boyd connects the dots.

July 2nd, 2000 and just another bunch of indie tyros release a song that begins: "Look at the stars, look how they shine for you". Coldplay's Yellow instantly became one of those very rare "event" songs, similar to Smells Like Teen Spirit in terms of how it would influence the musical generation that followed.

As Coldplay brought their nouveau-glum white indie sensitive rock to enormodomes around the world, a Starbucks-style explosion of their franchised sound has given us a small army of new Coldplays. All of them vigorously deny any sonic connection. Nevertheless, Snow Patrol, Athlete, Keane, Thirteen Senses et al all display a resemblance of sorts to the identikit picture.

At times it now seems that you can build your own Coldplay: learn Radiohead's The Bends off by heart, become solemn and sensitive, introduce a piano, throw on loads of strings to signify emotion, and write lyrics that convey a general sense of loss and disillusionment. Social issues are out, nihilism-lite is in.

Instead of citing classic albums as an influence, obscure literary types are alluded to. Every song should sound like you can hold a lighter up to it, and they should all possess some nebulous form of meaning - but not so much that it would scare off daytime radio.

It's got to the stage that an out-and-out punk-metal guitar band such as Feeder have to deny they're "doing a Coldplay" simply because they've introduced some softer melodic lines on their new album.

Popular rock music had crashed and burned in the immediate BC (Before Coldplay) years. Britpop had run its course and become an anachronistic embarrassment for all concerned; dance had necked one E too many and had to be held up as it staggered from the room. Into the music sales vacuum came a slew of Pop Idol acts who had severe difficulty even making it to their allotted 15 minutes.

R'n'b seemed to disappear as soon as Ms Dynamite went awol, and you knew there was trouble at music industry mill when Busted, a band who spent more on hair gel than on guitar strings, frat-boy'd their way on to the scene. Even the great white hopes, Radiohead, went on a head-trip, believing freeform space-age jazz to be the new black.

Coldplay were the sober equivalent to Radiohead's drunken splatterings. They had the talent to instantly escape the indie ghetto and get to that place where both the NME and Marie-Claire magazine would champion them. If the '90s could be summed up by that picture of an out-of-it Courtney Love exposing her breasts and falling off the stage, then that snapshot of Chris Martin playing the main stage at Glastonbury with a "Make Trade Fair" T-shirt a year later said it all.

Ironically, Coldplay owe a lot to grunge. Martin and chums would have been buying their first albums during the white heat of the grunge era. Certainly those "I hate myself and I want to die" lyrics and that general feeling of dislocation and detachment have fed into their songs.

Similarly, those great North of England bands - The Smiths (but minus the funny, camp bits) and Echo and the Bunnymen (whom Martin loves with a passion) had an impact on the tone of the music. If you had to explain Coldplay to aliens in two songs, it would be the Bunnymen's The Killing Moon and U2's All I Want Is You.

Multi-million sales later, and it's not so much that bands are photocopying Coldplay but that A&R people are signing up and encouraging bands to adopt a similar musical approach, which in their tiny little record company minds is "in fashion" and thus will ensure sales.

What's remarkable about the Keanes/Athletes/Snow Patrols is how they all write lyrics that make Chekhov seem frivolous. A content analysis of their songs throws up so many mentions of "pain", "blood", "tears", "goodbye" and, repeatedly, the phrase "leaving me". Tellingly, the hit single from Athlete's No 1 album, Wires, is about someone in hospital who's on a life-support machine. Even Kurt Cobain couldn't accomplish that.

Cynics will point out that on their previous album, Athlete were a chirpy cockney outfit suffering from a Britpop hangover who morphed into an intense and earnest band as quick as you could say "A Rush of Blood to the Head has gone No 1 in 28 countries worldwide". Similarly, Snow Patrol used to be a journeyman garage rock band before the career-salvaging Run single.

How much is internal band musical progression or external record company pressure to "chase the Coldplay dollar" is a moot point. And the sales figures for Keane, Athlete and Snow Patrol (Thirteen Senses now seem destined to be the Northern Uproar of nouveau-glum) render the argument academic.

And the second wave of this movement is about to hit us: waiting in the wings are a tearful amount of 17 years olds singing like they're Jean-Paul Sartre with a hangover and writing about how terrible everything in the world is. As Coldplay were the "new Radiohead" and Keane were the "new Coldplay", coming over the horizon clutching their debut single are the "new Keane".

It's historical inevitability - perhaps the only part of Marx that record company shareholders agree with.