Robert Schumanns poetic cycle Papillons and Finnish composer Kaija Saariahos quixotic Sept Papillons, for solo piano and solo cello, complement two noble sonatas by Franz Schubert and Benjamin Britten. Intrigued by the unusually tender and expressive qualities of the arpeggione – a bowed guitar held between the knees, in vogue for no more than 10 years – Schubert composed the Sonata in A minor “Arpeggione†in 1824. The great Russian ‘cellist Mstislav Rostropovitch was the inspiration for Brittens Sonata in C (1961), in which the instruments take on operatic roles, from the hushed opening, through dramatic tragedy to exuberant heights.