And it might be argued that, with personnel changes over its 59 years, the make up - and thus sound - makes for a "cycle" of Borodin Quartets. Only the cellist, Valentin Berlinsky, remains from the original line-up and that, alas, may need attention.The final concert in the cycle took place in the Fishmongers' Hall whose modest capacity is ideal for chamber music. Complete cycles of string quartets have long been the staple of festivals. Now it's the turn of the City of London to present the complete Beethoven in a series of concerts staged in six of the City of London's Livery Halls. The Borodin Quartet was founded in 1945 so has been playing cycles, arguably, longer than any other quartet. If that doesn't grab you, bad luck.Strictly speaking, added value can work only once, when artists are on their way up and need to stand out from their contemporaries. Yet the boundaries between formats are becoming ever more blurred.

The current "best of", Supergrass Is 10, offers a choice of the plain old CD or a two-disc DVD, including commentaries and the frankly terrifying "karaoke option". Ideally, we'd get basic commentaries on cut-price reissued CDs: Shaun Ryder, perhaps, admitting that he can't remember a single thing and telling a joke instead. (Sadly I suspect we'd just get musos mumbling about muso things instead.)Yet music alone can sell in huge quantities. Namedropping OutKast's Speakerboxxx/The Love Below might be as obvious as referring to Bill Hicks and Johnny Cash, but this sprawling though satisfying double has sold millions.

They do have a great image though, and from the highest to the lowest, it helps.. Hence the huge success of the Coldplays and Travises and Keanes, passing turns whose gimmick is the lack of anything but the music. It's hard to imagine, say, Morrissey kicking back and watching the racing while Radio 1 plays in the background, or Van Morrison picking up the grandchildren from playgroup. (Come to think of it, it's horribly easy to imagine Morrison doing that, but only as a minibus driver employed by the council.)After all these years they really are their own image, much like a long-running soap actor Relative dullards can be just as true to themselves too. As a distraction from the sight of a peculiar haired fellow seated at a piano, it succeeded, reviving memories of the lunatic Busby Berkeley-esque extravaganzas that made Elton synonymous with Seventies excess. Even Madonna is on tour, as usual distracting attention from her relatively weedy voice with the very definition of subtracted value, a cover of John Lennon's "Imagine".Of course some people don't need a gimmick at all.