The volume comprises a complete edition of the large manuscript Panciatichi 27, compiled at the beginning of the sixteenth century: 184 compositions (parts of masses, motets, Magnificat sections, litanies, lamentations, dances, instrumental pieces, frottole, laude, chansons, etc.). Nearly one-third of the compositions have Italian texts. The introduction takes into account the complex relationships with some 400 concordant sources, both poetic and musical, manuscript and print. Some compositions are closely related to printed sources of the early sixteenth century: several pieces were copied from publications by Petrucci and the Canzoni nove of Antico (1510), which helps in dating the manuscript. The work of a single scribe (apart from two pieces), the manuscript was evidently compiled for practical purposes, as is evident from the small format, the absence of decorative elements, erasures and corrections, alternative readings, duplications of parts of the texts, and the intriguing presence of arabic numbers at the ends of many pieces, related to the number of semibreves in the composition or its parts. It has been suggested that Panciatichi 27 was copied in northern Italy (Mantua or Ferrara); further evidence - in particular a repertorial connection with Augsburg, Staats- und Stadtbibliothek, MS 2 142a - points to Mantua. The commentary on each composition includes a complete list of concordances (many newly discovered) with bibliographical references and an evaluation of the relationships with concordant sources. Special attention is devoted to the Italian-texted pieces, where the critical commentary comprises the text as well as the music.