||Arbor 1, no. 3 (May-June 1944), 127-48. Rpt. in Hygini Anglés. Scripta Musicologica, ed. J. López-Calo, 3 vols (Rome: Ed. di Storia e Letteratura, 1975-76), vol. I, pp. 603-20.rn
||Snow 1977, no. 193, revised 2007: "For the layman, A. presents compact information on the notation of medieval European music and the CSM. Discussed are the exceptional musical techniques practised at Alfonso's court, the musical variety within the range of the CSM, and the import of such matters for modern musicological study. This version of the first part of the text of his monumental La música de las "CSM" (1943) tells how his study grew from idea to reality."