When you walk into a museum and find that your favorite Schieles and Munchs have all been rearranged to a particular configuration, you might wonder what the point is. Pianist Shai Wosner was a musical curator Friday night, but an inscrutable one, never explaining why he assembled the first half of his stunningly beautiful Philadelphia Chamber Music Society recital debut by interspersing Schubert impromptus with Chopin impromptus. Do they share more than a name?

Actually, it was a gift that Wosner was mum about motivation, giving his American Philosophical Society listeners license for imagination, and before long, you wondered whether the point wasn't about these two composers but a triangulation to a third. Schumann was never referenced explicitly, but as he was so ardent a Schubert admirer, you noticed how Schubert's manic traits became a route to Schumann's progressive ideas. Chopin's reputation now has been overtaken by his showpieces, but here, in Impromptus No. 1 and 3, we hear the same laughing gestures, impetuous mood changes, and breathless euphoria as Schumann. Wosner traveled from sound world to sound world with no break for applause. So who was the greater pioneer? Was Chopin more evolved than we thought, especially as he and Schumann share the same birth year, 1810?

If Wosner was being a sly revisionist, he was no less a sly player, shading Schubert's Impromptu No. 2 in A Flat Major, D. 935 as more dancerly than stately, and, thus, Chopinesque. He beautifully raised the variations of Schubert's Impromptu No. 3 in B Flat Major, D. 935 to its full tragic-comedic potential.

Three pianistic progressives - Beethoven, Ligeti, and Haydn - commingled in similar fashion during the second half. But for all the rhythmic and motivic connections laid bare, the more dazzling thread was the pianist himself. He used facile technique to wonderfully expressive ends, deploying each hand to pursue a different color in the Schubert Impromptu No. 4 in F Minor; and flavoring both Haydn's Fantasia (Capriccio) in C Major, Hob. XVII:4 and Ligeti's Capriccio No. 1 of 1947 with jaunty drama.

Beethoven ended, and came across as the supreme synthesis of the contrast explored by others. The Sonata in C Major, Opus 2, No. 3 alternates between Mozartean simplicity and great innovation, nowhere more so than in the second movement, which doles out initial material in doses cushioned by gracious silence, then veers into something darker. But Beethoven only provided the emotional suggestion. Wosner made it sheer terror.