Philadelphia Orchestra associate conductors are like U.S. vice presidents: They have huge exposure, a bit of dirty work to do, and ascend to the boss' job only in dire circumstances.

Nonetheless, Philadelphia's Cristian Macelaru (once associate conductor - new title, "conductor-in-residence") is making a more-than-vice-presidential career for himself. Last weekend, it landed him, on his own artistic steam, at New York's Mostly Mozart Festival, which gives significant platforms to conductors consolidating major careers, including the likes of Osmo Vänskä, Edward Gardner, and Yannick Nézet-Séguin. Good company? That's an understatement.

Now in his mid-30s, Macelaru has been hovering around New York, having conducted at the Caramoor Festival last summer with Joshua Bell and, this year, at Carnegie Hall with the Danish National Symphony Orchestra in place of the late Rafael Frühbeck de Burgos.

His relationship with the Chicago Symphony Orchestra began when Pierre Boulez canceled due to impaired eyesight, but who sat with Macelaru during rehearsals in what must've been the master class of a lifetime. That Chicago association has also yielded an occasional mentoring relationship with Riccardo Muti.

Saturday's Lincoln Center concert - Mozart's Symphony No. 39 and Beethoven's Piano Concerto No. 4 - belonged more to soloist Lars Vogt than to Macelaru: The concerto was in the second half, and the well-planned encore was the slow movement of Mozart's Piano Concerto No. 27. In contrast to Vogt's haphazard Philadelphia Chamber Music Society recital last season, he wowed the audience with brilliant passage work on the brightly voiced piano, almost entering the Lang Lang zone.

Yet the Romanian-born Macelaru's personality was ever-present. His Eastern European sensibility manifests itself in an instinctual preference for weightier sonorities. Often, you hear the change as soon as he steps before the Philadelphia Orchestra. And on good days, weight equals gravitas. On Saturday, for example, in the concerto's middle movement, where the orchestra confronts the pianist with stark block chords, Macelaru's treatment was all the more emphatic and implacable for being so cleanly voiced. The lean smoothness of the chords had the imperiousness of Darth Vader. No chink in that armor.

He wasn't entirely at home in the predominantly chic Mozart symphony; generally, he's best with music that has more stones in its shoe - minor-key Mozart such as the Requiem. Even so, this Mozart had the kind of truth-telling moment that happens often in his performances - the offstage day-of-judgment trumpet solo in Beethoven's Leonore Overture No. 3, the manically chattering piano in Stravinsky's Petroushka. In the Symphony No. 39 on Saturday, the flute solo that ushers in the anguished minor-key section of the second movement became your congenial if chilly guide to the underworld.

Such distinctive moments tell you there's an original musical thinker there, and you want more of it. This quality may also work against him. Conductors at his vice-presidential level have to assemble concerts quickly - usually one rehearsal at the Mann Center, though at least two for Mostly Mozart. You clearly know what parts of the program have received his full attention and what sections have not - in contrast to his Philadelphia Orchestra predecessor Rossen Milanov, whose approach to such concerts was greater consistency at the expense of peaks. Sometimes mistaken for a medium-voltage talent, Milanov had to get away from the Philadelphia Orchestra to show how good he really is.

Though not necessarily better, Macelaru is rising faster. My monitoring of his radio broadcasts - including a swift, heady Schumann Symphony No. 4 with the Detroit Symphony Orchestra - shows he has consistency, too. But when he gets stranded in the details, as he has occasionally in Philadelphia, his command of any given orchestra is such that the players are probably powerless to stop him.

But such moments aren't heedless or willful. Usually, Debussy's Jeux is treated as a compositional tour de force. Macelaru's Chicago Symphony performance went back to the music's balletic roots (it's a dance piece about tennis) far more than Boulez ever did, each moment striking out in so many directions with such purposeful physicality that the overall piece could have lapsed into episodic garrulousness. But it didn't. And my view of Jeux, which I've been obsessed with for 30 years, is forever changed.