[Young Turks; ]

For the average person, the maturity gap between 19 and 22 is sizable. For The xx, it’s a footnote. Notwithstanding the pubescent yearning of its lyrics, their self-titled debut was a stunning black-and-white crash course on restraint and poise, and they weren’t even old enough to drive when they started writing it. Three years later, there’s Coexist, and based on the impression left by its lead single “Angels,” this band’s learning curve is uncommonly flat.

If there’s one thing that’s immediately apparent about “Angels,” it’s the absence of co-singer Oliver Sim. On xx, his call-and-response vocals with Romy Madley Croft bred wonderfully open-ended questions. Are they supposed to be a couple? Can they hear each other? Are they specific people or just symbolic of the male-female duality? Here, Croft operates unopposed, delivering a simple love note to an anonymous recipient, and she does a magnificent job of carrying the piece on her own. If you tack on the velveteen guitar work, Jamie Smith’s deft production and the promise of something bigger waiting on the other side, there’s little doubt that The xx know how to hold an audience better than most.

Coexist is due out September 10 on Young Turks.