My vinyl copy of Captain Beefheart's Trout Mask Replica is a treasured thing – all four unlistenable sides of it – and it's there in my will as part of the motley collection of recordings I've amassed over the years. If I get hit by a bus today, my friend Jenny will get it, but the fate of the gigabytes of music I've bought online isn't so clear. Weirdly, they're not mine to bequeath; under the terms of license I merely have them on some kind of permanent loan.