Chopin’s last work was a cello sonata—the only one he wrote, and one of a mere handful of his compositions not exclusively for the piano. The inspiration in part was his cellist friend Auguste Franchomme, also something of a composer. With the Hungarian pianist Dénes Várjon, Steven Isserlis has framed Chopin’s sonata with the early Introduction and Polonaise brillante in C major, as well as Franchomme’s attractive if hardly remarkable Nocturne in C minor and Schubert’s ever popular Arpeggione Sonata in A minor (written originally for the near-extinct six-stringed, bowed, guitar-like arpeggione). From the majesty of the Chopin to the simple elegance of the Schubert, Isserlis’s singular mellow lyricism suits this repertoire perfectly. Várjon is deft and poised in accompaniment. The bonus is a Schubert song, Nacht und Träume, transcribed for cello and piano by Isserlis, an unmitigated nocturnal pleasure.