The title “Solo per il Violino” which Haydn gave these sonatas in his “Entwurf-Katalog” (the handwritten catalogue he maintained of his own works), already gives us an indication: it is only the violin which is treated as a solo instrument in these six sonatas the viola has an accompanying role. Haydn might have written these “soli” for himself- but they also might have been for Luigi Tomasini, the “first violinist” at Esterházy’s court. Today these duos enjoy great popularity, particularly for teaching purposes. We are now proud to present the definitive Henle edition following the text in the Complete Edition of Haydn’s Works with the addition of specially composedcadenzas.?