VINYL FORMAT. This Brooklyn group is led by Eleanor and Matthew Friedberger, who claim to be brother and sister. Unlike the White Stripes, who also say they're siblings, these two seem to be telling the truth, and they have the nonchalant stage demeanor to prove it. They generally ignore each other, the way only a brother and sister would. The album coheres around an unusual indie-rock instrument: the piano. There are angular ballads and off-kilter punk rants, and Ms. Friedberger delivers her lyrics with tight-lipped ferocity, turning the most whimsical tales into urgent announcements: 'I bought a tambourine at the Millennium Dome/It jangled two thousand times in a row.' Swaggering rock with a groove as sticky and grimy as a weeks-old flypaper.