Being experimental is all well and good when you've got something to experiment with. Unfortunately Grizzly Bear - four terribly unassuming men from Brooklyn in semi-matching polo shirts - seem to think that dabbling around in ineffectual stoner-folk territory counts as pushing boundaries, when really it just smacks of dreary self-indulgence.

In theory, it should be fantastic - harmony-flooded dreamscape pop with a pagan edge that transports you to America's great outdoors and brings to mind The Wicker Man and similarly sinister al fresco activities. In reality, their rambling, at times lurching, indie drags on in an uninspiring manner.

It's a shame, because there are moments of near genius among the tuneless rumblings and muffled attempts at banter that eminate from the stage. Frontman Edward Droste has a sublime, cooing voice, while drummer Christopher Bear plays his kit so enthusiastically that he breaks his floor tom halfway through the hour-long set. Songs like Fix It are languid to the point of horizontal, and plod on aimlessly as the near static audience show their appreciation with the occasional head-bobbing gesture. The tunes swiftly begin to mesh into one long piece that seems inert, no matter how many autoharps are bought out, and no matter how many whistled harmonies there are.

The over-riding problem is that the group have no real tunes, no wonderful melodies in which to let their mixture of glorious harmonies and wayward summertime blues shine.

Instead, they offer directionless dirges, as they simultaneously lean back, closed-eyes raised skywards, presumably blinded by what they see as the impressive clout of their material. For supposed Grizzly Bears, they're really rather tame.

· At Bestival, Isle of Wight, tonight. Details: 020-7379-3133.