The debut album from Australian duo The Avalanches began life as a mix tape they created to establish the perfect party soundtrack and mutated through the tangled thickets of copyright and clearance into "Since I Left You", and an astonishing beastie it has become. Rarely can a band have been so aptly named, because The Avalanches make music that sounds like the stock of a dusty, forgotten outback record store tumbling down the side of a mountain. Credits are given, but you'll probably swiftly tire of trying to spot just where the Madonna samples nestle up to the Boney M steals and the live action 'real' musicians and just surrender to this hour-long rollercoaster ride of an album. Somewhere on the same map as The Beastie Boys circa "Paul's Boutique" and Fatboy Slim, full of looped soul brothers and sisters, thin, swooping string samples and disco beats, "Since I Left You" is ostensibly divided into 18 different tracks, but so seamlessly do they interlock it would seem churlish to attempt to unpick them again. There's a real feeling of density here, of music so crammed with information and deeply layered that every listen reveals some new and unexpected twisty turn. You might not find yourself humming the tunes on the way out, but whilst you're experiencing The Avalanches in full flow you probably won't want to be anywhere else.