Dirty on Purpose made a promising but somewhat sketchy and soft-focus debut with 2004′s Sleep Late for a Better Tomorrow. Hallelujah Sirens is that record’s promise fulfilled: where the debut sounded tentative, these 11 songs are fairly buzzing with self-assured invention. The basic template remains exactly the same, with ethereal male and female vocals trading places over a wash of fuzzy, effects-laden guitars and simple, low-key rhythms. But the melodies are more memorable this time out, with greater sonic variation, richer arrangements and, on songs like the swooning opener “No Radio,” instantly memorable chorus hooks. Yo La Tengo is still the most obvious touchstone, although “Marfa Lights” has the buzzing, slow-build intensity of a classic Sonic Youth tune, and “Your Summer Dress” offers echoes of the Sundays’ diaphanous guitar shimmer. Overall, however, Dirty on Purpose have established a sound that’s recognizably their own. – Stewart Mason