San Jose-based headliners Xiu Xiu sound equally fragile on their second album, A Promise. Not necessarily instrumentally, since even when they're playing quietly, which is more often than you'd expect from a band on a Kill Rock Stars sister label, they're threatening to break out into one of the maelstroms of post-punk noise that eventually swallows "Brooklyn Dodgers"; closer "Ian Curtis Wishlist" eulogizes the Joy Division front man with a blast of little-star twinkles that smothers a Sigur Rós-style string drone. But, like Banhart, vocalist Jamie Stewart seems to view singing as an act of streaming consciousness: The band's cover of Tracy Chapman's "Fast Car" finds him mumbling through the lyrics, emphasizing certain words and phrases seemingly as they pop out on the page at him. A Promise is unsettling because you begin to fear that Stewart may say anything, and instantly regret it.