Instrumental music was widespread, but relatively few notated examples have survived. Indeed, while contemporary depictions of singers often show them performing from books or scrolls, paintings and miniatures of instrumentalists never show written music. The main keyboard collection is the Faenza Codex (Faenza, Biblioteca Comunale, ms. 117). Other small sources of keyboard music appear in codices in Padua (Archivio di Stato 553), Assisi (Biblioteca Comunale 187), and in one section of the (Paris, Bibliothèque Nationale de France, n. a. fr. 6771). The typical keyboard style of the time seems to have placed the tenor of a secular song or a melody from plainchant in equal tones in the bass while a fast-moving line was written above it for the right hand. The surviving sources are likely among the few witnesses of a largely improvised tradition.