"When it comes down to it, Bjork simply has no rivals for sustained pop innovation over the long haul." - Simon Reynolds

"I'm a very different musician to Coldplay. I like extremes. I think they probably like the middle a bit better than I do." - Bjork

So we come to the end of the 20th century. Let's leave it in the company of the last great pop star.

Is that a pose, a provocation? Well, yes, but I kind of mean it too. It seems to me that Bjork Gudmundsdottir represents the end of a tradition, one final, glorious flourish of what we have so often celebrated in this space week after week.

It's not that there isn't great music being made in the 21st century. Hopefully the coming weeks will prove that. But have there been any pop stars who are as ambitious and adventurous as those who went before? Have any offered an alternative way of looking at the world?

Yes, you could make a case for Andre 3000 and I'd listen. Beth Ditto, too, at a push. Jack White perhaps (but you'd have to get around his musical Luddite tendencies). I could understand someone offering Arcade Fire, but I'd need a lot of convincing. And I'm some distance from accepting any arguments for Lady Gaga (I'd be much more enthusiastic if she ever made a record that was anywhere near as exotic as she was).

And in a way Gaga is the ultimate symbol of pop's impasse. She speaks a good game, has the look down pat, but does she really stretch the envelope of what's possible?

Maybe I'd like her more if I liked her records. There's always a danger that, past 40, music fans suddenly realise that pop doesn't speak to them as much as it did any more and, as a result, intuit that it therefore can't be as good as when they were young.

I'm aware that I could be guilty of the same flawed thinking here but let me lay out my idea and you can decide.

Pop in the 21st century has, I would contend, returned to pre-Beatle values. It has been subsumed into - consumed by if you like - showbiz. Blame Simon Cowell if you like, but I suspect there's a bit more to it than that. Pop culture has been packaged up as gossip, as celebrity, as material for fashion advertising, as brand enhancement. "The Man" - remember him? - has won.

Yes, you might say, it was ever thus. Pop was always more commerce than art. Elvis may have started as a threat to western civilisation but he was soon making cheesy Hollywood movies. And I'd happily admit that if you gave me a choice between Britney Spears and Rage Against the Machine I'd choose Britney every time.

My argument, though, is that there is a strain of pop - starting with Elvis in his leather days, but coming into focus with the Beatles - that allowed, by accident or design, listeners to change their place in the world, that encouraged us to dream bigger. Pop as utopian practice if you like.

And so we come to Bjork as the last in the line, a line crowded out over the last few years by media white noise and possibly an absence of dialectic. If pop has been a champion of identity politics maybe it has now won all its battles. It has helped write gayness, blackness, female-ness and youth into the culture. Pop has won.

Well, it's just a theory.

I know all the reasons people don't like Bjork. The Icelandic pixie-elfin kookiness, a voice that can default to screechiness, a wilful experimentalism verging on inaccessibility and the hipster gloss that coats everything she does.

I don't see or hear any of that though. I see and hear a unique, ambitious, adventurous artist who has carved out her own sonic world. Bjork is sui generis. She sounds like no one but herself, even though she has always made music as a collaborative act (and over the years she has worked with Nellee Hooper, Tricky, 808 State's Graham Massey, Howie B, the late John Tavener and Matmos among others).

It's Howie B's version of All is Full of Love that graces Bjork's album Homogenic, but it's the single version that came out two years later that I prefer; a shimmering wash of a song full of electronic notes that ripple like water in a Japanese garden on which sails Bjork's voice, a soaring ethereal thing singing words full of humanity.

Chris Cunningham's accompanying video - in which two robot Bjorks make out - gets all the attention (and it is a gorgeous sci-fi dream of a thing), but the song doesn't need the eye candy. it's great in and of itself.

Back in Not Fade Away 1967 I said there were two songs played at my funeral, including that year's choice Sandy Denny's Who Knows Where the Time Goes. This is the other one. An aching, electronic balm to say goodbye with.

And as a postscript I'm going to say goodbye to Not Fade Away for a couple of weeks. My theory on the brokenness of pop art may be just that, a theory and a possibly tenuous one. But the brokenness of my wrist is a fact. This week's entry has been painfully, slowly picked out on the keyboard with one hand. I hope you don't mind if I wait before entering the 21st century until I am ambidextrous again. Updates on Twitter.

Other Contenders

Ms Fat Booty, Mos Def (a choice that doesn't totally go against the grain of last week's entry, although the title might, admittedly, lead you to believe so)

Supergrass, Moving

Basement Jaxx, Rendez-Vu

Chemical Brothers, Hey Boy Hey Girl

Moloko, Sing It Back

Aphex Twin, Windowlicker

TLC, No Scrubs

Eminem, My Name Is

Armand Van Helden, U Don't Know Me

Genie in a Bottle, Cristina Aguilera

Living La Vida Loca, Ricky Martin

Baby One More Time, Britney Spears

It's Not Right But It's Ok, Whitney Houston

Xpander, Sasha

Red Alert, Basement Jaxx

Sweet Like Chocolate, Shanks and Bigfoot

Breathe and Stop, Q-Tip

Caught Out There, Kelis

Thong Song, Sisquo

Windowlicker, Aphex Twin

Burn Girl Prom Queen, Mogwai

NME Single of the Year: Windowlicker, Aphex Twin

John Peel's Festive 50 winner: Cognoscenti vs Intelligentsia, Cuban Boys

And the best-selling single of 1999: Hit Me Baby One More Time, Britney Spears