Joseph Haydn's nearly forty piano trios are available in five volumes from G. Henle. These are based on the Haydn Complete Edition, likewise published by Henle. The fifth volume contains the six Piano Trios Hob. XV:27-32, which Haydn probably composed during his second sojourn in England (1794/95). He dedicated the first three to the then prominent pianist ''Mrs Bartolozzi'', who was born in Aachen ca. 1770 as Therese Jansen and had received piano instruction from Muzio Clementi. All six trios present a pianistic challenge and at the same time are sophisticated chamber music works. The G major Trio Hob.XV:32, however, is probably a violin sonata ''in disguise'', to which the violoncello part was subsequently added ''by a foreign hand''. Prefixed to this Urtext edition is a detailed preface by the editor that provides information about the works' genesis, sources and notational particularities.