James Blake could've become Sam Smith.
The two singers, both British men in their 20s, approach soul music as a kind of endlessly adaptable text, similar to the way Amy Winehouse and Adele did several years before them. Both have strong voices they only occasionally exercise at full power. And both balance natural good looks with a slightly sheepish charm that's endeared them to insiders and misfits alike.
But where Smith looks toward the center with big choruses and straightforward confessions -- and has been duly rewarded, as with the six Grammy nominations he received last week -- Blake keeps one eye on the margins, disrupting his traditionally rooted music with weird textures and poetic imagery.
"I don't wanna be a star," he sings in the title track of his latest album, "Overgrown," "But a stone on the shore / A lone doorframe in a war."
The 26-year-old singer-producer demonstrated that careful balance Tuesday night at the Roxy, where he performed for a capacity crowd that included many fans who knew every twist and turn in his songs.
Indeed, despite his professed disinterest in celebrity, some degree of it has materialized. Last year, he was nominated for a Grammy for best new artist, while "Overgrown" recently won Britain's prestigious Mercury Prize.
Accompanied by drummer Ben Assiter and guitarist Rob McAndrews, he began Tuesday's concert in sensitive-heartthrob mode, crooning Bill Withers' "Hope She'll Be Happier" over a sexy, slow-rolling R&B groove. That cover fed into a new song of Blake's in which he voiced a similar sentiment -- "I can't believe you don't wanna see me" -- as his bandmates measured out the head-nodding beat, thump by thump.
He showcased his florid singing later in beautifully stripped-down renditions of Joni Mitchell's "A Case of You" and "Limit to Your Love," the Feist song that Blake turned into a small-scale hit when he recorded it for his self-titled 2011 debut. In each, he'd elongate phrases according to his own internal rhythm, then hang back to let the sound decay, drawing your ear to the negative space he was carving out in the room.
Yet in other songs Blake left no space at all. For "I Never Learnt to Share" he used looping equipment to create a wall of densely harmonized vocals, while "Retrograde" built to a thundering climax of fuzzy digital noise.
"Suddenly I'm hit," Blake sang, describing the impact of a new love -- and of the song he was in the middle of performing.
"CMYK," an early single with vocals sampled from a track by Kelis, unfolded like a catalog of intense rhythmic ideas as Assiter moved from the harsh snare thwacks of the hip-hop variant known as trap to the steady 4/4 thud of house music to a propulsive beat that suggested an English version of reggaeton.
The musicians also did "200 Press," a hectic, bass-heavy cut from a new EP that Blake released Tuesday, and here they more or less managed to turn the Roxy into a dance club.
But only for a few minutes.
For an encore, Blake returned to the stage by himself to sing his song "Measurements," which with its gospel-inspired chord progression and its words about "faith in prayers" led one audience member to yell "Church!" at one point.
A few others in the crowd laughed, then everyone went silent again, intent on hearing this reluctant soul star as clearly as possible.