In certain circles, a classical pianist hasn’t arrived until she’s played all 32 of Beethoven’s piano sonatas, and Northwestern professor Ursula Oppens is in the midst of a three-year series of recitals that will cover the whole cycle. Better known as an exponent of new music, so far she’s included a recent commission on every program, bracketed by two or three of the sonatas–a format that invariably flatters the contemporary piece, drawing out its points of contact with Beethoven’s work. In turn, her eccentric performances of the sonatas–emphasizing abstraction over passion, powerful attacks over graceful gestures–have drawn out their latent modernism. At this concert, part of Northwestern University’s Winter Chamber Music Festival, Oppens will tackle a piece that seems even more at odds with her sensibility: Tchaikovsky’s Piano Trio in A Minor, which he composed upon the death of his friend, piano great Nikolay Rubinstein. Though it’s the best of his dozen or so chamber works, Oppens’s attempt to marry its folksy nostalgia and naked grief to her intellectual approach seems like mixing oil and water. It should be fascinating to see what the unflappable pianist does with this melodramatic music, full of extravagant passages meant to re-create Rubinstein’s virtuosity. Oppens will be more at home in Shostakovich’s Piano Trio no. 2, written to mark the 50th anniversary of Tchaikovsky’s death. It’s tighter in structure and more complex, yoking the playful diversions of some early piano trios to a bleak outlook. Her partners for both will be Portuguese-born violinist Gerardo Ribeiro, who also teaches at Northwestern, and Chicago Symphony Orchestra cellist Stephen Balderston. To open the program, Oppens and Ribeiro will play Schubert’s Sonatina in G Minor for Violin and Piano. Friday, 7:30 PM, Pick-Staiger Concert Hall, Northwestern University, 1977 South Campus Dr., Evanston; 847-491-5441. A preconcert discussion led by harpsichordist David Schrader begins at 6:15.