It's an indication of Josh Groban's vocal prowess that his new album of lung-busting Broadway ballads feels a little like a cop-out.
Before he recorded "Stages," which came out in April, the singer spent a few years venturing from the polished classical-crossover sound that made him a baby-faced sensation in the early 2000s. He'd grown bored with what he called a formula and turned to songwriting for the folky "Illuminations," which he made with Rick Rubin, and the more rock-oriented "All That Echoes," produced by Rob Cavallo.
Yet the experiment didn't quite work. Though both records sold respectably, they hardly transformed Groban into the pop star he seemed eager to become.
So it's easy to view "Stages," stocked with well-known tunes from "Les Misérables" and "The Phantom of the Opera," as a kind of retreat, even as it showcases singing well beyond most pop stars' ability.
Groban only deepened that impression Thursday night at the Dolby Theatre, where the native Angeleno played the first of two hometown concerts devoted to the album's repertoire.
As on the record, his vocals were strong throughout the two-hour show, with no evidence of the illness that he said forced him to call off several recent tour dates.
Backed by a small orchestra — and surrounded by glowing chandeliers and candelabra — he sang the stuffing out of "What I Did for Love," from "A Chorus Line," then went smaller and more intimate for "Try to Remember," from "The Fantasticks."
"Old Devil Moon" was lush and romantic; "Children Will Listen," from "Into the Woods," had a welcome touch of anxiety. And in "All I Ask of You," that reliable "Phantom" warhorse, he held his own against Lena Hall, the Tony Award-winning actress he brought onstage for a duet. (In an only-in-L.A. touch, Groban also invited up his old producer, David Foster, who said he'd been sitting with the singer's parents in the audience, to accompany them on piano.)
For all his power and precision, though, Groban seemed hemmed-in by the show's concept. He was expertly channeling the emotion of his material but adding little to it, as though he'd been shaken by what had happened when he'd tried to put himself out there.
That was especially apparent compared with the easy charm and quirky humor he flashed between songs in loopy banter regarding his history with musical theater (at school, he danced like Ralph Wiggum from "The Simpsons," he said) and the last time he was onstage at the Dolby (when he sang with Beyoncé at the Oscars, then regretted stealing her spotlight).
He also perfectly handled an overeager fan desperate to get a selfie with the singer in the middle of the show.
Groban brought that personality to his music in a handful of moments Thursday, most notably during a searching rendition of "Finishing the Hat," Stephen Sondheim's meditation on the challenge of squaring one's art with one's life. It was a theme that clearly resonated with Groban, who for the first time in the concert was really getting inside a song, owning it the way he did his own tunes on "Illuminations" and "All That Echoes."
He was good too in "Bring Him Home," the dramatic "Les Mis" chest-beater, which in an appealingly perverse twist, he presented in a hushed, hymn-like arrangement.
After that song, he apologized to the crowd for what he described as his highly medicated state. "I'm sorry I'm a little weird tonight," he said. But weird works for Groban. He shouldn't hide it.