The first time you listen to xx, the debut album by British quartet The xx, it is impossible to escape the feeling that it is somehow different from other recent releases. The reason why is not as clear. It isn’t the uncommon instrumentation (two guitars, a bass and a synth), nor the rich but unobtrusive production. The clicks and echoes of the drum track are unpredictable, but will not seem new to anyone even passingly familiar with a dancefloor; the lyrics are suggestive, but are neither precise nor evocative enough to be noteworthy. Only by listening to the entire album does it become clear: In the Age of Autotune, this is a record about the human voice.

The xx has two singers, man and woman, who trade lines and verses and occasionally blend in fragile harmony. The male voice is rich and insistent, the female breathy and more restrained. Neither is a “big” voice; range and power come in second to nuance and effect. This suits the subject and the form of the songs, which are set almost exclusively in the bedroom and the psychic terrain thereabouts. The lines “Maybe I had said something that was wrong/Can I make it better with the lights turned on?” are repeated again and again on “Shelter,” the breaks in the voices bursting like flares in a dark room, at once lighting it up and revealing its boundaries. Similarly, on “Stars” the male voice manages to bend improbable lines like “I can give it all on the first date” into shapes more fractured and complex than one would think possible.

If this sounds boring or somehow academic, it is only because the immediacy of the voices, unprocessed and urgent, needs to be heard to be understood. Much of the record sounds like Massive Attack’s Blue Lines, with the backbeat and scratching replaced by a more melodic and synthesized pulse, and the intensity compressed into a whisper. Again and again the two voices crawl inside a small moment and force it to expand, with the instrumental lines providing an intricate but repetitive backdrop against which the singing stands in sharp relief.

The rhythmic landscape of the album provides an important counterpoint to the vocal line. Synthesized snare, cymbal and bass drum hits serve a percussive effect, while the beat itself comes mainly from the guitars and bass. This lends an unusual and vaguely dangerous sense to the songs, as your expectations for their development are continually upended. Sustaining this for the entire album presents a paradox, however, as the band’s sound is so distinctive that the songs risk becoming indistinguishable from one another.

The pattern is broken by the sparse “Basic Space,” the clattering “Heart Skipped a Beat” (a standout track), and the drum-heavy “Islands,” although in this case the exceptions serve largely to prove the rule. “Crystalised,” the album’s most recognizable song, distinguishes itself less through difference than execution, more an exemplar than an experiment. The need for interaction between the vocals and the instrumentation is revealed, through its absence, on “Fantasy,” which consists of little more than the vocal track and some ambient noise and is consequently the album’s weakest song.

For all this, xx is remarkably simple. The complexities in the music are self-contained, the power in the vocals self-evident. What is truly remarkable about the album is its confidence to go small, to narrow its lens to an instant, a phrase, a lyrical turn. It is so much the louder for its quiet, so much the greater for its intimacy. The xx may not yet have a lot to say, but with their first album they have established themselves as a band with one hell of a voice.