The music made by England trio the xx can be hard to contemplate at face value because, in a sense, there’s not much there. And, much like their not-trying-to-do-too-much-but-already-iconic-somehow logo, that's completely by design -– their self-titled debut, which was something of an unexpected sensation, was built around spare, delicately constructed hooks, melodies, and simmering vocal interplay between singers Romy ...