The Cantigas de Santa Maria, a collection of over 400 songs praising the Virgin Mary and narrating her miracles, constitutes one of the most important collections of vernacular songs ('vernacular' in this case being Galician) to survive with their music from before 1300. The collection was assembled at the direction of Alfonso X 'The Learned', king (1252-84) of Castile and Leon, who may also have composed some of the texts and even melodies. The musical notation in the three surviving musically-notated manuscripts conveys the melodies without diffuculty to a modern reader. However, some aspects of rhythmic inter-pretation (i.e. the relative duration of the notational symbols, of which there are over 150) are still a matter for debate. A further important aspect is that the earliest form in which the corpus was put together-known as the 'Toledo codex', which contains about a third of the eventual repertoire-is encoded in a different (arguably earlier) form of musical notation. Almost all the pieces included for study in this volume survive in two different notational systems, to the advantage of the process of decipherment. This investigation takes as its corpus the first layer of notated cantigas, essentially those that survive in 'Toledo notation, ' although the notation of all sources is considered. This allows the differing notational codes to be compared, and valuable information to be extracted. What emerges from detailed analysis is a group of sixteen pieces, all making use of the same specific notational procedure for notating dotted rhythms in the absence of a half-beat symbol. Of the sixteen cantigas, eleven occur in the first 100 pieces, thus nearly quadrupling any previous estimate of the presence of pieces with dotted rhythm. In the analysis accompanying each piece, particular emphasis is laid on the correspondence of musical and textual stress, as well as on features such as regularity of musical phrase-lengths. The edited cantigas are embedded in the discussion and analysis, but are laid out as self-standing performing editions of the pieces concerned. An Appendix provides full editions of the original Galician texts-a feature not generally encountered in musical editions of the Cantigas-and full English translations. There are brief notes on syllable-division and word-stress for the help of performers. [Subject: Music Studies, Cantigas, Religious Studies, Catholicism, Medieval Studies