This is the third disc recorded by The Clerks' Group for their Signum Records trilogy. The series explores repertoire in the medieval period and culminates with a selection of works by Guillaume Dufay, found in one of the great anthologies of 15th century music: the manuscript Bologna, Civico Museo Bibliografico Musicale, MS Q15 (or "Q15" as it is known by its friends).The Q15 manuscript contains examples of almost every conceivable musical genre of the period by a vast array of composers. The Clerks' Group has chosen to perform works by a single composer, but still the variety of forms and styles on offer is bewildering. Guillaume Dufay was a composer who witnessed and contributed to most of the revolutionary changes to occur in music composition in the 15th century. The album includes some of the earlier works so often neglected from Dufay's repertoire, and goes on to explore compositions that demonstrate this revolutionary genius. Some compositional techniques celebrated by The Clerks' Group's performance include the playful exchange of Dufay's song-like melodies between the vocal lines; and the use of mensural canon, where the same melody is sung by all voices but at slightly different speeds. These are just a few examples of the radical nature of Dufay's music as demonstrated on this recording. The Clerks' Group brings immense diversity to the music and its performance. Their refreshing approach displays sincere empathy and passion for this astonishing repertory.