Scipione Cerreto, Dialogo harmonico, ove si tratta con un sol raggionamento di tutte le regole del contrapunto che si fa sopra Canto Fermo et sopra Canto Figurato, et anco della compositione di più voci, de canoni, delle proportioni et d'altre cose essentiali ad essa prattica musica (c. 1631). Manuscript preserved in Bologna: Museo internazionale e biblioteca della musica.

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37 duos; among them, six textless duos, eight duos with Latin texts, five madrigals, and 18 canons.

All the duos are scored in semibreve bars with the exception of the last two canons, which are notated on one barless line.

This treatise – in all likelihood never published – survives in two copies: the later, which I have analysed, is in Bologna; the earlier, compiled in 1626, survives in the Biblioteca del Conservatorio di Napoli. The treatise was probably compiled at the end of Cerreto's career and describes with plenty of details the technique of composing counterpoints on a given line, either a cantus firmus or a madrigalian voice. Furthermore, Cerreto cites two duo collections that he published, though these are now missing:

Five duos included in the treatise borrow from Francesco Corteccia's madrigal Fammi pur guerra, Amor (published in Arcadelt's first book of madrigals in 1539) and in all likelihood they were taken from the first duo collection. Furthermore, talking about enigmatic canons, Cerreto said to the pupil to study «Miei canoni che sono posti in stampa […] nel mio 2 libro a 2 voci intitulato Canoni Enigmatici».