Copyright and the Public Domain Authors own the exclusive rights to their compositions. This is called a copyright, and the composition is protected for many years--even if the copyright is never registered with the copyright office. A composition is considered to be "intellectual property" The copyright may be sold, transferred, or inherited--but the copyright still endures. If any music or lyrics are still under copyright protection you CANNOT reproduce the music or lyrics you CANNOT distribute the music or lyrics either for free, for no profit, or for profit you CANNOT perform the music or lyrics in public you CANNOT play a recording of the music or lyrics in public--even if you own the CD you CANNOT make a derivative work or arrangement for public use in any form Legally a copyright means that a musician, author, or artist has a "limited duration monopoly" on anything he creates. The US Constitution grants the government power "to promote the progress of science and useful arts, by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries." (Article 1 Section 8, US Constitution). To legally enforce an author's claim to his copyright, his work must be registered with the copyright office. Registering a composition provides public notification of copyright, and you cannot use the composition publicly unless you pay royalties--which can be substantial. If you use a song under copyright without the owner's permission, you are subject to legal repercussions. Public DomainFortunately, copyrights eventually expire and the owner has no exclusive rights. Also some composers renounce their copyright and give their music or lyrics to the public, either during their lifetime or at their death. All compositions which are not protected under copyright law are said to be in the public domain. If you can prove that a composition is in the public domain, you can arrange, reproduce, perform, record, or publish it. But you cannot just "know" a song is in the public domain or just "see" the name of the song in a book or on a list. You should use a public domain composition only if you have proof of public domain from a legitimate source.