And perhaps more importantly – who cares? If the impending closure of the obnoxiously “Web 2.0” BBC Sound Index this Friday is any guide, the answer is pretty clear.

Oh sure, the site boasts more than 22 million “comments, posts, plays and views”, but those comments and posts are all from OTHER sites like YouTube, last.fm, iTunes, myspace, and the like. Sound Index sent automated “robot” scripts to these sites looking for the names of bands, fed what it found into some kind of magic algorithm, and produced a constantly updated list of the 1000 buzziest bands on the planet. Or well, the English-speaking planet. Probably. Slap some shiny, gumdrop-like buttons on the results, organise things with a direct rip-off of the iTunes “Coverflow” feature and hey presto.. well, what exactly?

The subcontractors who made it, Nova Rising, had some heady early expectations that it could be “the chart to replace the Top 40”. And indeed, the TV show Sound (for it is that which the Index is named after) is the BBC’s attempt to make up for the lack of live chart music on television precipitated by the cancellation of Top of the Pops.

One could argue that the Top 40 was the original “web 2.0” concept. The songs are all written, performed and recorded by other people; their order of presentation each week is determined by millions of people’s individual listening and buying habits; all you have to do is play the songs. Brilliant! For Top of the Pops you’d have to invite a smelly band or two, but even the dancing bits were “user generated”. Just turn on the cameras and away you go.

But Top 40 radio shows and Top of the Pops were popular, when they were popular, because we understood how things worked. If a band sold enough records, it would be – or should be, with ensuing debate – invited on the show. There was no mystery about why a song had reached number one – it had sold the most. But Sound – and even Top of the Pops near the end – introduced a nefarious editorial element. Why are these bands playing?

And with the Sound Index it’s even less clear. The algorithm Nova Rising used for trawling through other sites’ comments threads was developed by IBM and has apparently cost a fortune. IBM’s presentation of some of the challenges involved says that “online comments are absolutely the worst way to find out what is popular… except for all the other ways.”

So, is money really obsolete? Do sales really rate less than 10,000 variations on JAN47 from TAMPA, FL’s contention that “ONE NIGHT ONLY ROX”? I don’t think so. Ultimately the only people who care about this kind of popularity – i.e. aggregate internet buzz – are record labels, and it has been pointed out that they already have Music Week for that sort of thing already.

For those who do care about the pop music horserace of the charts, the Top 40 still exists. And in the absence of a real chart show you can do what my friend Josh and I did when we were seven or eight and had the use of a real cassette tape recorder all to ourselves. You can sing your own versions and play them back, collapsing in laughter. Hey, maybe we could YouTube it. Then we’d get in the Sound Index!