Johannes Tinctoris, author of twelve extant theoretical works, is usually seen as a man of scriptura, the written word. But cantare supra librum, a practice he describes in Liber de arte contrapuncti, has much in common with oral traditions. With cantare supra librum, a singer reading a written-out cantus prius factus devises ex tempore—a line that obeys the rules of counterpoint. As with oral repertoires, performer and creator are the same person; creation takes place at performance speed; and creation is governed by “constraints”—i.e., generally accepted rules.

Tinctoris’s distinction between cantare supra librum and res facta (which Tinctoris defines as cantus compositus) is central to his thinking. Most musicologists assume the difference between the two to be that res facta is written out while cantare supra librum is not. Dissenting from this view is Margaret Bent, who argues that the distinction is between performances that do or do not meet the condition that each voice obey the rules of counterpoint with respect to all the others.

This paper will extend Bent’s argument, maintaining that orality is key to Tinctoris’ thinking and that for Tinctoris the important distinction is between performing from a text and devising a contrapuntal line during performance. A careful parsing of relevant passages will show that by identifying res facta with a text we are imposing a modern view of the “work” on music for which the “work concept” did not exist. Significantly, Tinctoris uses “compositus” not in the modern sense of writing out a composition but in the Humanist rhetorician’s sense of being well organized. Tinctoris belongs to both the textual and the oral worlds, and he writes at a moment when an influential oral practice was being assimilated into the written tradition.