Of all the varied strands woven into the cultural fabric of Renaissance Italy, the most vivid in the quattrocento was that associated with the study of ancient literature christened "humanism" by nineteenth-century scholars. Aristotle's analysis set the agenda for humanist debates about the role of music in elite education. The idea that the history of music could be represented as a narrative of progress from generation to generation is only one example of the ways in which rhetorical literature was to influence how humanists understood and analyzed music. The earliest humanist criticism arose in the mid-fifteenth century from efforts to establish moral criteria for distinguishing good and bad music. Johannes Tinctoris's impressive musical scholarship probably played some role in winning acceptance for famous composers and singers as artists worthy of respect. The music being sung in courts, whether monodic, homophonic, or polyphonic, was increasingly written by professional composers and sung from printed books.

The mensural system of rhythmic notation used in the fifteenth century, musica mensurabilis, was largely inherited from earlier centuries. This chapter focuses on aspects of the mensural system that led to the most interesting features of fifteenth-century rhythmic style. It describes current scholarly arguments about aspects of fifteenth-century notation. Students who learned mensural notation in the fifteenth century most likely did so from a textbook that was a century old, the Libellus cantus mensurabilis attributed to Johannes de Muris. For the modern musician reading fifteenth-century notation, imperfect notes are very close to modern note shapes, since they are the origin of binary system. Johannes Tinctoris's highly polemical remarks about improper use of proportion signs in Proportionale musices are both entertaining and enlightening for the modern reader. By the early fifteenth century, successive diminution of a tenor line was generally not written out but signaled by a verbal canon.

Matters of solmization, mode, mensural rhythm and notation, and counterpoint received many theoretical treatments over the course of the fifteenth century, often as part of ardent polemics. The evolution of the music treatise is the objective of this chapter. Several subgenres of the music theory treatise emerged: One can find encyclopedic approaches as well as topic-by-topic organization, and summaries of and commentaries on earlier theoretical traditions as well as cutting edge responses to modern musical practice. Johannes Tinctoris certainly participated in a widespread fifteenth-century tradition of prescriptive responses to current musical practice. The chapter explores how this spectrum of subgenres impacted the treatment of a common set of music-theoretical subjects. To consider this question, the chapter surveys several Italian treatise subgenres, including the encyclopedic summa, the notebook and compendium, the dialogue, the laus musicae, and the focused treatment of notation, counterpoint, and mode. Finally, the chapter concludes by pondering the readership of these theoretical writings.