The members of Sonic Youth have been so prolific in the past few years, it's difficult to decide which albums, offshoots, and solo projects transcend the band's tendency to fall back on wanky exercises in fractured noodling. From several installments in a trilogy of improvisational, experimental EPs to a collection of old tracks by guitarist and occasional vocalist Lee Ranaldo, 1998 has been an especially product-intensive year for Sonic Youth, and the results have all been spotty. The group has always been unpredictablethat clashing of ideas is a big part of what has made Sonic Youth both great and legendary for 17 yearsbut on the new, 74-minute A Thousand Leaves, that means a tendency to allow songs to devolve into detached, pretentious exercises like the 11-minute "Hits Of Sunshine (For Allen Ginsberg)." As always, inventively tuned guitars squawk, squeal, rumble, and ramble, and once in a while, as on the nine-minute "Wildflower Soul," the band gets something going, building to an almost hypnotic climax. But too rarely does A Thousand Leaves contain fully formed songs: "French Tickler" is gutsy and potentit should make a good follow-up to the deadpan single "Sunday," which benefits from a compelling, droning guitar soundbut much of the album's remainder is bogged down in endless excess. Sort-of frontman Thurston Moore has joked that the new record is called A Thousand Leaves because it's part of a 1,000-album series, but since it's taken this long to do 14 of them, that probably won't happen. Here's hoping Sonic Youth bears that in mind and starts completing its ideas before recording them for posterity.