This cycle comprises Haydn’s 39 authenticated multi-movement solo keyboard works from 1765 onwards (all called Sonatas here, using modern nomenclature), and nine earlier works (CD8) that are presumed his, or probably his, by the vast majority of scholars.

Careful detective work on the authenticity of a number of works from Haydn’s youth is still evolving, but I have limited my cycle to works that are included in Anthony van Hoboken’s and Christa Landon’s lists of Sonatas, except fragments, works that have conclusively been shown not to be by Haydn and those over which significant doubts are raised.

Early works found in Hoboken’s and/or Landon’s catalogues, but not included as part of this cycle are: • L. 21–27 (Hob. XVI:2) – These seven Sonatas, for which we have incipits, were lost, probably in a fire. • L. 17–18 (Hob. deest), L.8 (Hob. XVI:5), L.10 (Hob. XVI:1) – Severe doubts exist as to their authenticity. • L.57 – This has been shown not to be authentic. It uses two movements from L.19 (Hob. XVI:47), transposed up a semi-tone.

• L.28 (Hob. XIV:5), L.5 (Hob. XVI:11) – These works exist only as fragments. • Hob. XVI:15 – This is an arrangement, not by Haydn, of the Divertimento in C Hob. II:11 • Hob. XVI:16 – Severe doubts exist as to its authenticity. • Hob. XVI:17 – This is by Johann Gottfried Schwanenberger.