The sparse simplicity of The xx‘s critically acclaimed debut, 2009’s xx, belies the kind of songwriting effort it takes to write such a consistently engaging album. Unlike some of the band’s London-based, indie-rock contemporaries (such as previous tour mates The Big Pink)—which hit audiences over the head with bombastic hooks—The xx lures listeners in with a laid-back subtlety that is no less effective despite being significantly more economical. It’s an even more impressive feat given the fact that the album is self-produced; there’s no big-name producer or other outside influence telling keyboardist Jamie Smith, guitarist Romy Madley Croft, and bassist Oliver Sim how their songs should be packaged—because the trio already knows what makes their reverb-heavy, minimal pop work. (It involves a lot of back-and-forth male/female vocal exchanges.) The xx performs with experimental rock quartet Warpaint and lo-fi goth chanteuse Zola Jesus at 8 p.m. at Merriam Theater; tickets are $28.50.