The Korean pianist Yeol Eum Son has attracted admirers in venues of multiple types: in the buttoned-down world of the classical music competition, and in the broad popular arena of YouTube, where a video of Son performing the Mozart Piano Concerto No. 21 in C major, K. 467, has attracted some ten million views. Son chooses that concerto for her Mozart debut, and here she has the added advantage of backing by Sir Neville Marriner and the Academy of St Martin-in-the-Fields.

This release by violinist Viktoria Mullova and pianist Katia Labèque (their labels, Labèque's KML and Onyx, which Mullova helped found) sees both these well-known artists stepping out from their usual roles. Mullova has been an impressive exponent of the major violin concertos who has moved into Baroque music in recent years with some success, while Labèque is known for her duo-piano work with sister Marielle (KML stands for Katia and Marielle Labèque). They fill their new roles not just adequately but spectacularly.

Not autumnal, not reflective, not reserved, and definitely not restrained, this coupling of Brahms' two string sextets may seem to some to be at best wrong-headed and at worst simply wrong. After all, isn't Brahms the composer for whom the adjective autumnal was coined and to whom the adjectives reflective, reserved, and restrained are reflexively applied? Yes, but that doesn't mean all of Brahms' music is autumnal: he was young once, too and the expansive and exuberant young Brahms is emotionally far from the reflective, reserved, and restrained composer of later years.

The outstanding young German pianist Joseph Moog makes his debut on ONYX with a superb disc of two great Russian piano concertos that have had very different fates. Anton Rubinstein s 4th was once one of the most famous and popular concertos in the repertoire, and many of the major virtuosos performed this work into the early years of the 20th century when the composer s other works vanished from the concert hall.