These twelve compositions were part of Zarlino's didactic illustration of compositional theory and practice. Because they appear in a theoretical treatise they have not attracted much attention as legitimate compositions to perform. Despite the context in which they appear, these are no mere theoretical exercise, but display Zarlino's genius in exploiting the musical potency of modal harmony and counterpoint. They are technically very easy, but sublimely beautiful, the aural effect being one of transparency and strict modality. The allegiance to the plainchant origins of some of the melodies is at times very obvious. No specific instruments are specified in the source, but the pieces suit viols perfectly.

The edition includes a score and two part books arranged so that each part is available in a choice of clefs (bass or alto).