The oddest, most audacious disc of the year? Matthew Herbert has taken Mahler's final completed orchestral movement, the adagio of his 10th symphony, and re-recorded it in various death-related venues – a coffin, a crematorium, Mahler's composing hut – mixing in sounds of nature, adding a viola solo. It is not so much a recomposition as a manipulation of an existing sound source (whose conductor is not around to object). "We filled the work with ghosts," says Herbert. It might surely work as a film, or even a radio documentary, while as a CD it is certainly clever and atmospheric – but what does it communicate?