||Snow 2007: "We are treated to some valuable ideas, the result of much study. For example, the author finds the notation (brevis/semibrevis) of To to be, quite possibly, a breakthrough in the progress towards the 'ars nova'. Based on a study of intervals and other musical factors, he finds that the CSM are 1) not popular melodies — any popular elements have been absorbed and recontextualized, and 2) clearly designed for professional musicians. The design of the MSS seems to argue against free circulation of the musical texts, although there were designated moments of the Mass, for example, which allowed such songs to be performed. Clearly further study is warranted along these lines. Finally, some of the deficiencies of the Anglés transcriptions  are pointed out."