Debuts as fully formed and confident as the xx's self-titled first album are rare, but then, there is very little that is typical about this band or their music. Their influences are wide-ranging -- traces of post-punk, dream pop, dubstep, indie pop, and R&B pop up at any given moment -- but are focused into songs that are as simple as they are unique and mysterious. These tracks are so sleek, they're practically sculptural, and they boast impeccably groomed arrangements. The beats pulse rather than crash; the guitars are artfully picked and plucked; and the vocals rarely rise above a wistful sigh. This restraint and sophistication make the fact that the xx's members were barely in their twenties when they recorded the album all the more impressive; artists twice their age would be proud to call the maturity and confidence that flow seemingly effortlessly through the xx their own. Even their song titles are the perfect mix of concise and evocative: "Stars," "Shelter," "Night Time" (actually, all of their songs could be named this -- they're that intimate and sleepily cool). The moody, monochromatic sound the xx sets forth on "Intro" is lovely enough, but it's how the band subtly shifts and tweaks it on each track that makes the album truly special. "VCR"'s innocent guitars hint at the band's fondness for Young Marble Giants' radically simple indie pop, while "Infinity" leans more heavily on their post-punk roots, and "Heart Skips a Beat" underscores its name with wittily fractured rhythms. And while singers Romy Madley Croft and Oliver Sim sound good on their solo turns (Sim particularly shines on the spacious "Fantasy"), together they're truly inspired -- the aloof sensuality they generate makes romantic intrigue actually intriguing again. "Crystalised" might be one of the more intense songs here, but it still carries the confessional quality of a conversation between lovers, reaffirming what "heart-to-heart" really means. The standout "Basic Space" takes Croft and Sim's push-pull chemistry in an even more pop direction, but it's still awash in subtly fascinating details like its exotically rolling beat and Durutti Column-esque guitars. While the band's subtlety and consistency threaten to work against them at times, XX is still a remarkable debut that rewards repeated listens and leaves listeners wanting more.