@Lyendith from the little I could understand from french wikipedia, Rédaction seems pretty close to the meaning of Redação in Portuguese, which is a more general term for writing or composing text.
But in english, from my research, Redaction doesn't have this general meaning, instead having mostly to do with text editing. One of the most common dictionary definition is something like "the process of removing words or information from a text"(cambridge dictionary), with sligthly different meaning also given "a form of editing in which multiple sources of texts are combined (redacted) and altered slightly to make a single document"(wikipedia), and also "The process of editing text for publication" (oxford dictionary).
Given the context, the more appropriate word to use there would be "essay" or "
composition", but I'm also not a native english speaker so I can't be sure which choice of words would be most natural there.
edit: I think composition wouldn't be good there because of the interaction with sheet and the musical meaning.
(Also I'm starting to think there's no equivalent concept in English for the sheet. Maybe change the phrasing for an equivalent that doesn't need the word?)