Jessie Ware started out as a backing singer, and she still has the sensibilities of one. Although Ware’s Mercury-nominated 2012 debut, Devotion, vaulted her from supporting player to headliner, she seems not to have made the mental leap. Playing to a noisy room full of iTunes competition-winners, she is an oddly unobtrusive presence. She is here, yet apparently assumes it’s someone else’s job to be the star.

Ware’s lack of ego shows in her appearance: her hair is pulled out of the way and her black outfit, topped off by a diaphanous train attached to her shirt, ensures she blends into the monochromatic set. Yet it’s a fitting way to convey her music, which is so drenched in shuddering sub-bass and soulful trills that “star” conventions go out the window. Ware and her four musicians are a package deal, creating lush electronic peaks and chasms. Only occasionally does Ware break out to reveal a voice heavy with lovesickness.

She tells us she got married three weeks ago, yet some of the tracks premiered from her new album, Tough Love, are squalls of frustration, brought about by the tendency of love to not do what you hope it will. “This is about me waiting a while for him to put a ring on it,” is her introduction to You & I Forever, while Cruel’s Adele-like sumptuousness counterpoints the lyric, which implores a certain someone not to be “so cruel to me”. And the song Kind of … Sometimes … Maybe achieves a knife-edge balance between the xx-style electronic minimalism and fretful jazz murmuring.

She showcases her elegantly restrained vocals on the single Wildest Moments, from Devotion, and a new Radio 2-ready ballad Say You Love Me. They round off a show that is both a study in reticence and a welcome return for a head-turning vocalist who may yet develop a relish for the spotlight.

• At St John at Hackney, London on 2 October. Details: jessieware.com. Then touring.
• Jessie Ware on Tough Love, working with Miguel and getting mobbed in Poland