Described in 1840 by Robert Schumann as comprising ‘four unruly children smuggled under this name into a place they could not otherwise have penetrated’, Chopin’s Piano Sonata No 2 is now a stalwart of the repertoire, and for this new recording by Benjamin Grosvenor it sits alongside No 3—an altogether more ‘conventional’ work—and four of the composer’s indelible shorter masterpieces.