This year's list has pectoral idols Take That rubbing shoulders with the cerebral composer Michael Nyman. Rock comebacks Paul Weller and Ian Webb stand alongside pop brats Pulp and hardcore ravers the Prodigy. If Lord Reith were chairing the judging panel, the Mercurys couldn't be more public-service.
But is this inclusiveness a strength? There's an argument that the Mercurys are a last-ditch attempt to preserve the 'classic' days of British pop, when every kind of music rubbed up against every other in the Top 40, producing bizarre, world- conquering hybrids.
This is no doubt the secret dream of the pop scholars and magazine contributors who make up the Mercury panel. Their comments strain for authority ('consummate pop', 'a driving and relentless album'), clearly hoping to produce a Booker-like consumer fever for quality rock.
But the writing is on the wall for this Arts Council-like ethos. Narrow-casting is the future. As in America, radio stations are targeting much more specific musical tastes. JFM is branching out of London, Country stations are springing up from Glasgow to London. Adult Contemporary formats - from the Stones to Simply Red - dominate regional radio while dance and rave pirates blast out their coded message to Generation E.
The face-off between Virgin 1215 and 1 FM is improving the listener's overall choice - as did the old TV duopoly between ITV and BBC. But all these developments are dissolving the idea that definitive national institutions can be all things to all pop listeners. Is it really that important for the country's musical health that we should appreciate the symmetries between Gary Barlow's choruses and Michael Nyman's cadences? Rave bands like the Orb are quoting Stockhausen and John Cage anyway. Who needs the pundits?
Some might say this is an argument for an American-style fragmentation, with charts and stations for every taste, and 'crossover' the elusive prize. Wouldn't there be a real loss if British popular music descended into musical apartheid? That depends on whether the Mercurys and kindred institutions are about rock as culture or as industry.
The extraordinary health of the American music industry - and the relative decline of our own - would seem to make the eclecticism of the Mercurys the worst possible model for boosting sales. Perhaps the narrowness of US formats and charts means that American artists make better, more effective music of each particular kind, keeping committed audiences happier.
What used to be Brit-pop's advantage - our island crush of classes and cultures - is now an industrial disadvantage in the global market-place. The fact that you don't know exactly what to expect from Brit pop these days is the problem, not the solution. The blurring of boundaries, beloved of rock judges and musicians, is exactly what format programmers around the world hate.
So if the Mercurys really aren't that good a marketing tool for the beleaguered biz, what good are they? We could value them as a statement of what is singularly good about British pop culture, its diversity and fluidity. And damn the multinational consequences. So it's appropriate that Blur's Parklife album should be the favourite to pick up the prize on 13 September: gleefully raiding the last 30 years of pop, quoting greyhound racing and Tony Benn in the same breath. But will it sell in Peoria? The Mercury's limited worth is that it allows British musicians a day to avoid that thorny question and celebrate pop art, not pop commerce. Rock on, Lord Reith.
Pat Kane is a member of the band Hue and CryReuse content