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. This fourth volume contains the nine Piano Trios Hob. XV:18-26, which Haydn probably composed during his second sojourn in England (1794/95). Prefixed to this Urtext edition is a detailed preface by the editor that provides information about the trios' genesis, dedicatees and notational idiosyncrasies. The piano largely dominates in these ''sonatas for the pianoforte with accompaniment of violin and violoncello'', as they were titled in the first edition. In fact, for long stretches the violin doubles the right hand of the piano at the unison (with the violoncello doing the same for the piano left-hand part). The two string instruments nonetheless contribute significantly to the impact of this music, and the violin is occasionally entrusted with the melodic line on its own.