Open one free score's editable downloads (MusicXML, MXL, MIDI, ABC, MEI) and remove its PDFs' footer line by spending exactly unlock_credits (15) of the account's existing credits, once per score; edits and later revisions stay open. Call only after the user explicitly agreed to that exact number in this conversation; credits must equal access.unlock_credits and consent must be true. An already open score (paid band transcription, Plus, earlier score) is never charged. Never offer purchases.