For example, Bono made an offer to the former German Chancellor, Gerhard Schroeder, which he couldn't refuse: he was facing an extremely difficult election which, as you know, he ultimately lost, and Bono made the offer that if Schroeder came up with the necessary pledge then, during the course of the upcoming U2 concert in Germany, he would proclaim the Chancellor's virtues from the stage, which he did. And so a kind of deal was struck. So these people have real power, and they are listened to by billions of people.

DJ: At the intellectual level too we take them seriously in a way in which perhaps we didn't used to. The December issue of Standpoint is an example of this - it's got David Bowie on the cover. And yet, Ian, you have your doubts about how far popular music deserves this sort of accolade, taken from a musical point of view.

IB: It deserves to be taken seriously because it seems to have become so important, but what I find difficult about it is its level of false consciousness. It's pre-eminently a youth culture - the change in it today, I suppose, is that 50 is the new 30, and people can now continue to listen to pop music and be influenced by it at an older age - but musically it's not very interesting. And it's odd that we should take so seriously something that as music per se is not really being pursued at a high level. I mean, the whole thing about art is its increasing complexity and reflexivity and the thing about pop music as music - not necessarily as social commentary or even as art in a more general sense, but just as music - is that it's not really reflecting upon itself very much.

TB: I have a great deal of sympathy with that, especially about certain forms of pop music, and I think that's where the problems start. If you lump it all together in one single category like "pop music" then one is going from something which anyone can see is primitive to a degree, like the "The Smurf Song" - I can't think of anything more awful than that, can you? - to, on the other hand, some very ambitious musical creations: I suppose the classic case would be Sergeant Pepper, or more recently the kind of things that someone like Elvis Costello does. In the house of "pop music" there are many mansions, and some of them are small and very squalid and can be seen in a matter of the blink of an eye, and some of them are really very grand indeed. Pretentious in some cases, yes.

But I think that this is where Ian and I fall out probably - one criterion I quite like is durability. And if popular music which was being played in the 1960s is still being played in 2008, then it must have something if it can say something to each succeeding generation. Some of it has endured, and that suggests to me that it has a quality which must be musical in some way, even if the actual structure of the notes on the score - if there were a score, which in many cases there wasn't - is very simple.