Gather your evidence. Include a recording of your music and sheet music or printed lyrics where applicable. Mark each piece with the date on which it was created, and the date when it was recorded.
Place your evidence in the padded envelope, and seal it. The Canadian Music Publishers Association (CMPA) advises that mailing yourself the evidence is the easiest and least expensive way to copyright your material.
Write the name of the song or other composition on the back of the envelope.
Send the package to yourself by registered mail. Registered mail provides firmer documentation of the postage date.
File the package in a safe place after it arrives. DO NOT OPEN IT. Should you ever need to prove authorship of your music, the package can be opened in court, but it must remain sealed until then.