The first articles here focus on Johannes Tinctoris, the prominent late 15th-century music theorist. They deal with the discovery of his lost pedagogical motet, and his treatise on counterpoint; this forms the basis of a wide-ranging investigation of contemporary practices of improvisation and composition (singing super librum and writing res facta), in which the question of 'successive' and 'simultaneous' composition is reconsidered. Tinctoris's sometimes sharp rebukes to famous composers are also investigated in the context of works by Ockeghem. Ottaviano Petrucci's first publication of music, the 'Odhecaton' of 1501, is the subject of another three articles. These identify the editor of the work, and make new proposals on the provenance and editing of this repertory. The last article presents an edition of a treatise of ca. 1600 in the form of a letter from the virtuoso cornettist Luigi Zenobi to an unknown prince, which offers new insights on the change in performance practice at the end of the Renaissance.