The Allegretto from Schubert’s “Three Piano Pieces,” D. 946, was a gently rocking barcarolle. Any notes Schubert put on paper turned into a song, and the song was always present here, supported but never swamped by the swirling piano writing….The Brahms’ Opus 116 was masterfully played. “Petrushka” made something clear about that masterwork too: It had to be about puppets, not humans. From the famed “Russian Dance” to Petrushka’s scurrying flight from the murderous Moor, it was all bright, clattery, nervous, even its violent outbursts on a smaller-than-human scale. Von Oeyen made all that clear with breathtaking panache.