Beethoven: Duos for Viola and ViolinOnyxViola players are always complaining they get overlooked. Not by young Beethoven, it seems. There’s a 1799 sonatina in C for viola and cello lying around in manuscript at the state library in Berlin, and a 1796/7 duo for the same instruments in E flat. Both are full of the joys of spring, rippling with dance rhythms and an invitation to waltz the night away. There is a suspicion Beethoven played the viola part himself in at least one of the works, writes Professor Barry Cooper in a lucid sleeve note to this interesting release.The duos, however, are the sum of Beeethoven’s viola parts. The rest of this album consists of arrangements – a viola-piano setting of the string trio opus 8 by William Primrose; and, best of all, a conversion by Maxim Rysanov of the opus 11 clarinet trio for viola, cello and piano. The switch works for the late Brahms clarinet sonatas and positively soars in Beethoven.Rysanov, a BBC New Generation Artist, plays a gorgeous 1780 Guadagnini with the flair and hunger of a formula-one driver. He takes the bends at speed and challenges the rest of the field to keep up. The highly spirited musicianship is shared, bend for bend, by Kristina Blaumane’s cello and Jacob Katsnelson’s piano.3 Mahler CDsStenz: 3OehmsMarkus Stenz and the Gurzenich orchestra of Cologne delivered one of the most invigorating Mahler 5ths of recent years. The 3rd is less coherent, with too many stop-starts and too little irony in the opening movement; insufficient tension, too, in the marvellous concluding adagio.Kreizberg: 5OPMCYakov Kreizberg, who died last year, was immersed in the language of Mahler and Shostakovich. This live recording of a September 2010 concert of the 5th symphony with the Monte-Carlo Philharmonic is not without flaws, but you will seldom hear a more dancing, mocking, life-affirming realisation of the difficult Scherzo, ahead of the evanescent, eternally ambiguous Adagio. The performance demands to be heard.Haitink: 9BR KlassikHaitink has long sought to de-emotionalise Mahler. It’s an interesting exercise in some symphonies, but never in the 9th where Mahler pushes himself to the edge. Of Haitink’s several recordings, this is the least convincing – though tautly played by the Bavarian Radio SO with a stunning concertmaster solo in the finale.___Norman Lebrecht is a regular presenter on BBC Radio 3 and a contributor to the Wall Street Journal, Bloomberg and other publications. He has written 12 books about music, the most recent being Why Mahler? He hosts the blog Slipped Disc.