Round-numbered anniversaries provide cover for performers inclined to explore the more obscure corners of a composer's catalog. And as this week's St. Paul Chamber Orchestra program shows, when the composer is Robert Schumann, who was born 200 years ago, those corners are well worth exploring.

Schumann's "Introduction and Allegro appassionato," Op. 92, and his "Introduction and Concert Allegro," Op. 134 -- both for piano and orchestra, the latter dedicated to the young Johannes Brahms -- don't quite fit the boxes of concert life. (Nor do they win points for creative nomenclature.) Written for Schumann's wife, Clara, one of the foremost pianists of her day, they require accomplished soloists but are too compact to fill the concerto "slot" in a conventional program.

The SPCO's solution is to play both pieces in the same concert. Friday, in the first of three performances this weekend, pianist Jonathan Biss -- who last year gave a memorable account of Schumann's A-minor Concerto -- and conductor Roberto Abbado made a stronger case for the arch-romantic Op. 92, which begins with a gently gorgeous horn call and seldom flags. The late, piano-dominated Op. 134 felt a bit meandering despite Biss' mastery in the cadenza.

Still shy of 30, the pianist seemed particularly attuned to the composer's mercurial fantasy, his signature weave of drama and dreaminess.

Schumann's wonderfully idiosyncratic "Overture, Scherzo and Finale" requires no anniversary; from the Beethoven-like gravity of its slow introduction to the majesty and tenderness of its crowning Allegro, this foreshortened symphony merits frequent airings. In the hands of Abbado (who will lead the orchestra in two more mostly Schumann programs this month), its drive and charm were irresistible, its second-movement Trio especially delicate. Orchestral balances, often iffy in Schumann, were irreproachable.

An otherwise all-Schumann program may not have been the ideal launching pad for Steven Stucky's Chamber Concerto, an SPCO commission that premiered Friday with the composer (winner of the 2005 Pulitzer Prize) on hand.

Though a professor of composition at Cornell University, Stucky is no mere academic scribbler. His Chamber Concerto is lyrical, colorful, atmospheric and, in its dark Largo section, gripping; it also manages to evade the self-congratulatory quality that bedevils scores written to exhibit the virtuosity of their players. Which is not to say that the orchestra, under Abbado's tension-sustaining baton, was anything less than brilliant.

Larry Fuchsberg writes regularly about music.