2 vihuelas at the fourth. Vihuela 1 [vihuela mayor] is easy [primero grado]; vihuela 2 [vihuela menor] is medium difficulty [segundo grado]

Valderrábano gives this piece in the title as being by Mouton. Tom McCracken confirmed in personal correspondence to John Griffiths ( 21 March 2014) that the work is in fact not by Mouton, but by Gombert. Gombert’s Paine et travail me font incessament." is published in his Opera Omnia (CMM Series 6, vol. 11 [1975], pp. 212-16). McCracken’s new edition of Mouton’s Opera Omnia is due to be published in 2014. The chanson volume (Volume 5) will explain the situation. Dr Mc Cracken forwarded the relevant text prior to publication where he comments on Valderrábano’s setting: “... the duet version omits 25 measures of Gombert¹s music, starting at Letter I (m. 55). This may have been a deliberate decision by Valderrábano, or else an accident either on his part or by his printer. On the other hand, on purely chronological grounds Valderrábano¹s exemplar must have been different from the unique surviving source for Gombert¹s chanson (London, British Library, Reference Division, Department of Manuscripts, MSS Royal Appendix 49­54), forwhich a dating of c. 1565­-80 has been suggested.[1] He may, therefore, simply have reproduced both the version and the composer¹s name he found in his exemplar; it is unlikely we will ever know who was responsible for either omitting the missing measures or the attribution to Mouton.[2]
[1] Herbert Kellman, ed.. Census-Catalogue of Manuscript Sources of Polyphonic Music 1400­-1550, Renaissance Manuscript Studies 1 (5 vols., Stuttgart: Hänssler-Verlag, 1979­88), 2:108, citing Jane A. Bernstein, ³The Chanson in England 1530­-1640: A Study of Sources and Styles² (Ph.D. diss., University of California at Berkeley, 1974).
[2] While it is theoretically possible that the London manuscript¹s attribution to Gombert (rather than Valderrábano¹s to Mouton) is the incorrect one, this seems unlikely since the piece is stylistically unlike any of Mouton¹s other chansons.

This misattribution was reported by Ward (ward1953 409 and 414)