Traditionally, the relationship between text and musical setting has not been deemed to be a very close one in sacred music of the 15th century. Music theorists do not begin to address questions of text underlay and text declamation systematically before the 1530s, and the co-ordination of words and notes in the sources is not as precise as modern editors would like it to be; it has therefore proven difficult to establish any firm 'rules' for this period. This book proposes an approach through which this 'problem' can be largely solved. Both the sources and the music itself suggest a distinction between intrinsically 'declamatory' and intrinsically 'non-declamatory' passages or pieces. In turn, the rhythms of the declamatory passages or pieces show a very high correlation between musical rhythm and text type: prose texts are set with the prose accent as primary criterion, verse texts according to verse rhythm, metrical poetry according to various models. This system of declamatory models or patterns corresponding to text type is derived from the simple polyphonic settings (laude, cantiones, liturgical recitation), but can be successfully extrapolated to the most complex compositions of the time. These models or patterns do not necessarily correspond to what today would be considered 'good' or 'correct' text declamation which has led to the questionable reputation of 15th-century polyphony in this regard. Nevertheless, they remain stable throughout the period examined and even beyond it. In fact, it is argued that the rise of 'correct' declamation in the 16th century is not the result of a new, humanistically inspired attitude towards the word (and its meaning), but a shift from a predominance of setting verse (rhythmical or metrical) to a predominance of setting prose.