Youthful embraces and lonely leave-taking occupied each half of the Philadelphia Orchestra's Thursday concert at the Kimmel Center. The two halves shared unexpected characteristics: unguarded emotionalism unlike anything else heard from the respective composers, whether in Bartók's

Violin Concerto No. 1

or Bruckner's

Symphony No. 9

.

Smartly devised by music director Yannick Nézet-Séguin, the concert had long-term contour. It started with Barber's famous Adagio for Strings, burning slowly from within, its pathos-ridden climax downplayed so as not to detract from the Bartók concerto that followed - whose first movement is a long, fearlessly rhapsodic song, sounding little like the mature composer who filtered emotions through ingenious structure. This fragile concerto is the kind of piece that a composer writes only once, and therefore occupies a singular place in the repertoire, despite its derivative language and having only two movements.

Nézet-Séguin connected with the piece more than guest soloist Lisa Batiashvili. This superb, world-class violinist played with lyrical sweetness, but the conductor found extra momentousness in some of the smallest details, such as the oboe entrance.

Like the program's other works, the three-movement Bruckner symphony doesn't fall into a conventional format. When last heard here under Jaap van Zweden in 2009, was a clear, clean triptych of intricate musical architecture. Instead, Nézet-Séguin mined the piece's narrative, showing how much it stands apart from Bruckner's others.

The third movement was divided into three sections by daring rhetorical pauses, signaling structural turning points in the music, but also feeling like switchbacks in a long mountain trail - into the hereafter - with moments of agony and trepidation. All Bruckner symphonies involve a religious quest, but Nézet-Séguin touched on an element I don't hear in others: religious doubt, and the profound loneliness that comes with it. Other Bruckner symphonies have a chorale embedded in them. I've yet to apprehend one in the 9th - and felt its absence as never before.

The performance itself still had a little ways to go. Augmented by Wagnerian tubas, the Philadelphia Orchestra (or any orchestra) rarely projects such a muscular sonority. Passages that always go out of tune (yes, always) did not do so on Thursday. However, tension flagged occasionally in the first movement's more digressive moments. The third movement's wonderful three-note viola motif, so haunting in Nézet-Séguin's Orchestre Métropolitain recording, was fuzzy and only semi-audible. In an odd way, one was grateful the performance wasn't all that it could've been. Anything so emotionally raw seems too personal to hear in public.

The concert is repeated at 8 p.m. Saturday at the Kimmel Center.

Information: 215-893-1999, www.philorch.org.