Gary Cooper and Rachel Podger’s projected set of the Mozart duo sonatas (of which this is the second volume) will be more complete than most, including the works he wrote for keyboard with accompanying violin between the ages of seven and 10. Of course these can’t be compared to the later sonatas but they’re certainly not without interest; and on the present disc the progress between No 2 and No 15 is striking – the latter’s Adagio shows an enormous increase in expressive range (further extended by Gary Cooper’s extravagant decoration of the repeats) with the violin complementing the melody most effectively. The decision to use the same fortepiano for all the sonatas may not be the most accurate historical way of presenting them but, as Cooper points out, it does help the listener to hear them as belonging to a single line of development.

Both artists show an impressive command of the rhetorical 18th-century approach to phrasing and expression, giving a very lively air to the music-making – there are no flat, routine moments. The theatrical manner of No 18’s first movement inspires a wonderfully bright, colourful performance, and the contrasts inherent in the two-speed opening movement of No 20 are brilliantly realised.

Some listeners may find the continually active style of playing a step too far, and there were places, in the first movement of No 33, for example, where I’d have welcomed a calmer, less eventful approach. But the great Adagio of this sonata has a beautiful sense of line and, throughout, the marriage of expertise and stylistic awareness results in truly treasurable performances.