"Of course we were nervous," says bassist Este Haim of recording the L.A. sister act's debut album. Between opening gigs for Mumford & Sons and Rihanna, the trio hit the studio with producer Ariel Rechtshaid (who has worked with Vampire Weekend and Usher). The resulting LP is packed with rich harmonies – check the Fleetwood Mac-ish single "The Wire," which the band recorded 10 times before finding the right groove. "We love organic and electronic instruments," says Haim. "The amalgamation of the two is what excites us."