2 vihuelas at the fourth.
Vihuela 1 is easy [primero grado], vihuela 2 is medium difficulty [segundo grado]
Re vocal work, see: Anglés, Morales, Opera Omnia III, Texto, 35; Lewis, Gardano, 589; Pogue, Jaques Moderne, 202; Stevenson, Cathedral Music, 72; Schöner (1999), 216-217. Schöner, 134-35, argues for the Dorico print as a possible model as there is evidence of large numbers of this book being imported to Spain, however, Valderrábano’s setting reproduces an important error from the 1540 Scotto edition.

Additional copies of the polyphony:
Cividale del Friuli, Museo Archeologio, MS 53
Madrid, Biblioteca Medinaceli, MS 607
Reggio Emilia, Archivio della Parrocchia S. Prospero Città, MS, sin sign.
Rostock, Universitätsbibliothek, MS Mus. 40
Stuttgart, Württembergische Landesbibliothek, MS. I.28
Vatican, Cappella Sistina, MS 19