On two impressive EPs, Maps & Atlases crafted a kind of math-pop, where complex rhythms and scales fit into somewhat conventional song structures. On its debut LP, the group is still perfecting the concept. With upped production and widened stylistic diversity, Perch Patchwork makes exploratory expeditions into psychedelic folk, prog, and art-rock, but ultimately doesn’t set up camp anywhere. As always, extravagantly complicated guitar work, unusual drum patterns, and bursts of bass showcase flawless technique; more than ever, these are seamlessly integrated with tempo and key changes. Layered with harmony and powered by Dave Davison’s strong vocals (at times resembling Cat Stevens’), the record develops a consistent atmosphere that’s mostly calm and pleasant. Too much so: Most of Perch Patchwork’s songs beg to be built up and given weight, but the group chooses not to augment its technical prowess with drama. The airy “Banished Be Cavalier” and “Israeli Caves” bounce and bob like a leaf in a mountain stream, but never go anywhere; “Pigeon,” with a sparse guitar riff and world instrumentation that recalls Paul Simon’s Rhythm Of The Saints, is agreeable yet forgettable. It all ambles along to the title track, where string arrangements and softly overlaid chanting drift to the album’s quiet close. For a debut, Perch Patchwork feels oddly transitory, but suggests good things when the band decides what to transition to.