Joint Works and Copyrights
When a copyrightable work is created by two or more persons, ownership of the copyright can take several forms, depending on the intent of the parties.
When two or more people create a work with the intention that it be a collaborative work and that one copyright cover the work as a whole, it is considered a collaboration. In such cases, the creators become joint owners of the copyright. Imagine two people go on a trip with the intention that one writes about the trip and the other takes photographs. To confirm that this is the understanding of the parties, a written agreement should be signed.
A collective work is generally a compilation, such as a magazine, newspaper, or other periodical, in which a number of separate and independent works are compiled into one work. If you have written an article, column, or short story that has been published in such a compilation, you may make a separate registration for your work. Your work would be a “contribution to a collective work.”
For example, if a number of freelance poets give their permission to have their poems published in a poetry anthology. The freelancer owns the copyright to their individual contribution, and the publisher owns the copyright to the anthology.
A derivative work is a work based on or derived from one or more already existing works. If the material of an existing work is made into a new work but is used in a different way than originally created, the resulting work is a derivative work.
For example, if a film that is based on a novel is a derivative work. If parts of a previously-written musical score are used in the film, the resulting film is a derivative work based upon both the novel and the music. The creator of the film is entitled to a copyright. If the novel and the music are still under copyright, the creator of the film needs to get their permission (and pay for a license) before using their works.
For copyright purposes, a work is only considered derivative if it uses substantial amounts of an existing work and adds new original copyrightable authorship to that work.