A song consists of two types of music copyrights: composition (or musical work) and sound recording.

• Copyrights in the song composition protects the combination of aspects like the melody, harmony, and lyrics. It provides the basic melody and establishes the fundamental character of the work. Ownership of the song composition is represented by the © symbol.
• Copyrights in the sound recording are created each time the song composition is recorded. Each performance will be original and, when recorded, fixed in a tangible format. When identifying the rights owners in a sound recording, ownership in a particular sound recording is represented by the ℗ symbol.

A common misconception is that a copyright registration creates copyrights or establishes ownership. Copyright is inherent upon the creation of a musical work. Your song is protected by copyright law as soon as it is fixed in a tangible format whether it is a recording, tape, music sheet, etc.

Musical works and recordings are both intellectual property with their own rights and attributes ownership to a specific composition and recording. Copyrights give you exclusive rights as an owner to generate a source of revenues.

So why do people officially register their work with the copyright office of their country? 

• A copyright registration is the best evidence you can produce of your ownership of a work. 
• You must have a registration on file in order to take legal action against an infringer.
• Registering your song within three months of its publication allows you to seek statutory damages for infringements that took place prior to registration

In Canada, a copyright lasts for 50 years after the author (or the last surviving author) dies. In the United States, it lasts for 70 years after the author (or the last surviving author) dies. Some exceptions apply such as Fair Dealing (in Canada) and Fair Use (in the United States). 

Note: Policies differ for every country and territory. Make sure you verify the laws that apply to you or consult a legal practitioner.