It’s no accident The Fall sounds so casual. Gorillaz recorded the album on Damon Albarn’s iPad during theirU.S.tour last year. Unlike the group’s other three records, The Fall (which was originally released to fan-club members as a download late in 2010) isn’t a meticulously arranged work. In fact, it sounds more like a tossed-off road diary, with songs reflecting various tour stops: “Detroit,” “The Snake in Dallas,” “Bobby in Phoenix.” The best tracks here – the instrumental “Phoner to Arizona” and the mournful “Revolving Doors” – wouldn’t sound out of place squeezed into the album Gorillaz released last year, Plastic Beach. But The Fall is more experiment than essential.