United States copyright law
from https://en.wikipedia.org/wiki/Copyright_law_of_the_United_States
The Copyright Law of the United States tries to encourage the creation of art and culture by rewarding authors and artists with a set of exclusive rights. Copyright law grants authors and artists the exclusive right to make and sell copies of their works, the right to create derivative works, and the right to perform or display their works publicly. These exclusive rights are subject to a time limit, and generally expire 70 years after the author's death. In the United States, any music composed before January 1st, 1923, is generally considered public domain.
United States copyright law is governed by the Copyright Act of 1976. The United States Constitution explicitly grants Congress the power to create copyright law under Article 1, Section 8, Clause 8, known as the Copyright Clause. Under the Copyright Clause, Congress has the 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.
The United States Copyright Office handles copyright registration, recording of copyright transfers, and other administrative aspects of copyright law.