What is Copyright?
Copyright is one of three types of laws (the others being trademarks and patents) through which congress exercises its constitutional authority "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." (U.S. Const, art. I §8 cl.8)
These exclusive rights are cumulative and may overlap. The exclusive right to perform a work publicly is limited to "literary, musical, dramatic, and choreographic works, pantomimes, and motion pictures and other audiovisual works," (17 USC 106(4)) and to sound recordings in the case of digital audio transmissions (17 USC 106(6)).
The U.S. copyright law is contained in the U.S. Code, Title 17. Section 106 lists the exclusive rights, while sections 107-122 cover limitations in the scope of copyright.