Column: Modern music blurs classic genres Though, as with most things, it is the matter of some debate, many popular music critics acknowledge that The Beatles seminal 1967 record "Sgt. Pepper's Lonely Hearts Club Band" marks the point at which rock music began to be taken seriously — as art. That said, precisely how highly we regard the album is of less consequence than the influence it has had, or, at least, been seen to have had on how we think about this particular brand of entertainment.

Prior to this, despite — or perhaps because of — remarkable sales of all types (especially in comparison to today's numbers), pop music was purely diversionary and ephemeral. But thereafter, a rich field of criticism has grown up to separate the wheat from the chaff in this corner of mass culture.

The battle probably has not been universally won, there continues to exist a certain attitude towards popular music that doesn't take it as seriously as, say, jazz or classical, but criticism stands in very different stead today than it did in the early sixties.

Indeed, the most interesting debates these days about musical criticism come from within the community rather than from the outside. There is very little noise to be heard from classical aficionados seeking to disparage popular musical generally and, if anything, the cacophony of undeveloped criticism blows in the other direction. However, there is plenty of dissent to be heard among popular music critics when it comes to the issue of genre.

 Terminologically speaking, popular music has seen a dizzying diversification and multiplication of genres and sub-genres in recent years, but there remains perhaps one big debate: rock versus hip-hop.

"Sgt. Pepper's Lonely Hearts Club Band" also, more loosely, marks the end of The Beatles' career as a live act. Moreover, it stands as an early testament to the powers of studio recording to produce arrangements of sounds which simply could not be reproduced on stage. Though the chasm that opened between studio and stage with the release of this record has decreased significantly, there is still a particular attachment to seeing music performed live that most, if not all, music fans share.

This summer, we are in the midst of festival season where tens of thousands of devotees make pilgrimage to remote locations to see their artists of choice in person.

Britain's most famous of these, the Glastonbury Festival held in the south-west of England, has just taken place and was the scene of the most recent flare-up in the rock/hip-hop conversation. Glastonbury holds a special place in the hearts of many rock music fans because it represents, in a certain sense, and certainly coincides with the rebirth of rock music in nineties Britain after the long winter of the eighties.

This year, Jay-Z, perhaps the most celebrated hip-hop artist of the last decade, headlined the event much to the chagrin of Noel Gallagher, songwriter, Beatles devotee and guitarist for one of the 90s most celebrated rock acts: Oasis.

The argument, insofar as one was made, was essentially a purity argument, i.e. Glastonbury is for guitar acts, not for hip-hop. Hip-hop would taint the festival. Of course, there is a sense in which this has been true historically, in that the vast majority of artists to ever play the festival have been of the guitar persuasion. But Jay-Z is not the first hip-hop artist to appear in the mud at Pilton, merely the first to headline, and thus the case seems less strong given this pre-existing impurity.

Pushing the notion of purity even further damages the argument even more. Hip-hop is the product of the same musical lineage that rock considers itself a part of — a lineage dating back to jazz, the blues and beyond.

Rock aficionados often have uncommon respect for the immediate predecessors of hip-hop: soul and funk music, but somehow fail to appreciate the apparent caprice of capping their musical interest in black-inspired music in 1979. It's all the fruit of the same tree.

This is not a paean to uncritical thought, however.

I still expect bad rock and bad hip-hop to be called by these names and castigated for falling short on their respective scales of achievement. But the notion of a true separation between the styles is just superficial. It reminds me of the highly counterintuitive "racial" fact that there is greater generic variation within "racial groups" than between them. That is, there is no reason to presuppose that members of a particular "racial" group will have more in common with their fellow members than they do with members from other "racial" groups.

We think we can see differences and indeed we can, but they don't matter from a biological point of view. I contend that the apparent differences between rock and hip-hop don't matter from a musicological point of view. Music criticism is about making distinctions, of course, but the right distinctions, not the wrong ones.

Jay-Z opened his set with that classic Oasis track "Wonderwall." I hope Noel enjoyed it.