At the Kimmel Center Saturday night, it was theoretically possible to hear Beethoven's

Violin Concerto

twice.

Julia Fischer was in the big hall, Verizon, with the Philadelphia Orchestra. Fischer, at a ridiculously young 23, is the most highly polished violinist you're likely to encounter, and already near the top of an international career.

In the smaller hall, Perelman, Astral Artistic Services was hosting Korbinian Altenberger, 25, who played the Beethoven with the Haddonfield Symphony Chamber Orchestra. Altenberger is a student at the New England Conservatory, where he studies with noted pedagogue Donald Weilerstein.

Altenberger and Fischer are both Munich natives, and that might be about all they have in common. Fischer (whom I heard Friday night) is a poised and arresting figure on stage. She moves and bows her head slowly and regally. Her facility and accuracy are astonishing, and she found an unusually variegated range of colors in her first-movement cadenza. She is extraordinarily able, if not extraordinarily interesting. Hers is a Beethoven concerto that looks down from an Olympian perspective.

Altenberger, on the other hand, is still asking what the piece is all about, and finding some fascinating answers. He struggled a bit, yes, with intonation. And the cadenzas were pieces in themselves, so long they started to sound self-indulgent. But he also consistently made his phrasing mean something, and that something in the second movement was a deeply wonderful expressiveness.

It would be fun to report that the youthful enthusiasm of the Haddonfield players outshone the jaded old Philadelphians, but, in fact, Haddonfield, with about two dozen musicians led by Rossen Milanov, sounded thin and slightly amateur. Despite the fact that the Philadelphia Orchestra sometimes had a hard time forming unison attacks under Christoph Eschenbach, the strings were lustrous, and two instrumentalists stood out as especially elegant: hornist Jeffrey Lang and bassoonist Mark Gigliotti.

Astral's talent-spotting and -cultivating mission spoke for itself in the rest of Saturday night's program, in which cellist Min-Ji Kim took Hindemith's Kammermusik No. 3 for Cello and 10 Instruments to some bleak, moving depths; and in Shostakovich's Concerto No. 1 for Piano, Trumpet and Strings, where trumpeter Christopher van Bergen was solid, and pianist Michael Mizrahi filled out his part with an exceptionally strong and charming personality.

Back in Verizon Friday night, Eschenbach spent the second half of his program with a signature piece of Berlioz. It might be possible as he enters the homestretch of his tenure that Eschenbach will have come and gone without evolving much as an artist. His Symphonie Fantastique had all of the characteristics of his usual approach. The orchestra's sound had a hard edge in the first movement; ensemble attacks were often not in unison; and extreme tempo changes were used for no apparent expressive reason.

Players must assume the blame, however, for some of the troubles of the third movement. The offstage oboist was painfully out of tune, and the English horn player spoke through a brittle tone.

Great moments do happen under Eschenbach, and this third movement came with one, at the climactic middle stretch, where he and the orchestra reached a state of tremendous frenzy without losing a drop of ensemble accuracy.

Contact music critic Peter Dobrin at 215-854-5611 or pdobrin@phillynews.com.

There are no additional performances of the Astral concert. The Philadelphia Orchestra program is repeated tomorrow night at 8 p.m. in Verizon Hall, Broad and Spruce Streets. Tickets are $10-$113. Information: 215-893-1999 or www.philorch.org.