Brahms, Robert & Clara Schumann, Dietrich. Isabelle van Keulen (violin), Ronald Brautigam (piano) (Koch Schwann). Schumann, Goetz, Brahms, Dietrich. Patricia Verhagen, Paul Kohnen (piano duet) (Globe)

Keulen and Brautigam handle Clara Schumann's Op 22 Romances and Brahms's G major Sonata with a gentle inwardness that serves them well. The real interest on the disc, however, is the sonata Brahms wrote jointly with Robert Schumann and Albert Dietrich for the great violinist Joseph Joachim. It's an interesting if unbalanced piece, of which only Brahms's Scherzo has remained in currency. Dietrich's achievement was constrained by his strict Schumannesque ideals, Hermann Goetz's by his early death. Their duet sonatas here usefully illuminate two hardly more familiar works by Brahms and Schumann.