The Divertimento for String Trio K. 563 is, by common consent, one of Mozart’s very greatest chamber works, right up there with the “Haydn” Quartets and the String Quintets. Up until now the only version I knew was an 1982 recording by the Vienna String Trio, only available now as an MP3 download. I bought it upwards of 20 years ago and it’s a very fine recording except that the finale is just a bit too slow. This began at last to exasperate me until my search for an alternative led me here. It’s quite as good as that other recording plus the finale is just the right tempo.The story behind the two duos for violin and viola is well known, how Mozart had returned to Salzburg for a visit to introduce his new bride to his father and sister and learned that his old friend and colleague Michael Haydn was unable to complete a commission for six duos due to illness (though his indisposition was more likely due to his chronic alcoholism). Given the circumstances and the limits of the medium one might have expected mere throwaway stuff but the duos turn out to be first rate top drawer Mozart. Amusingly, the liner notes state that “To Haydn’s great relief, the archbishop who commissioned them failed to notice the deception.” (Right. You pay for Michael Haydn duos and get fobbed off with Mozart. I can see how that would be annoying.)The greatness of these three works is something of a well-kept secret judging by the paucity of recordings, making this an attractive package. As if that weren’t enough you also get Mozart’s arrangement of six Bach fugues, five by J.S. Bach and one by son Wilhelm Friedemann, for string trio. The J.S. Bach fugues include three from the Well Tempered Klavier (the d minor from Book I and the g minor and F major from Book II), number eight from Die Kunst der Fuge (was this Mozart’s favorite? It’s mine too!) and the third movement of the trio sonata in c minor. The fugues from Die Kunst der Fuge have often been performed by string quartet or string orchestra; the ones from the WTC sound so good I wish I could hear more of them that way. That this hasn’t been done more often is no doubt due to the fact that it would leave the preludes, which are idiomatic keyboard music, orphaned. To fill the gap here Mozart wrote his own preludes for four of the fugues. Incidentally, the W.F. Bach fugue in f minor comes from a set of eight organ fugues, F.31. It’s also a superb piece.The early Sonata for two violins and cello K. 266 is a minor but pleasant work. First movement exposition repeats are taken in the Divertimento and Duos.