These actions were brought to restrain infringement of the copyrights of two certain musical compositions. Apollo (D) is engaged in the sale of piano players and player pianos, and perforated rolls of music used in connection therewith. P brought these actions under the provisions of the copyright act. The testimony discloses that certain of these rolls, used in connection with such instruments, and being connected with the mechanism to which they apply, reproduce in sound the melody recorded in the two pieces of music copyrighted by P. The manufacture of such instruments and the use of such musical rolls has developed rapidly in recent years in this country and abroad. The record discloses that in the year 1902 from seventy to seventy-five thousand player pianos were in use in the United States and that from one million to one million and a half of such perforated musical rolls were made in this country in that year. The musical rolls consist of perforated sheets, which are passed over ducts connected with the operating parts of the mechanism in such a manner that the same are kept sealed until, by means of perforations in the rolls, air pressure is admitted to the ducts which operate the pneumatic devices to sound the notes. The perforations were so arranged that the effect is to produce the melody or tune for which the roll has been cut. The parties to this action advance opposing theories as to the nature and extent of the copyright given by statutory laws enacted by Congress for the protection of copyright, and a determination of which is the true one will go far to decide the rights of the parties in this case. P insists that it is the intention of the copyright act to protect the intellectual conception which has resulted in the compilation of notes that, when properly played, produces the melody which is the real invention of the composer. P claims the protection covers all means of expression of the order of notes which produce the air or melody which the composer has invented. D contends the extent of this protection is a matter of statutory law, that it has been extended only to the tangible results of mental conception, and that only the tangible thing is dealt with by the law, and its multiplication or reproduction is all that is protected by the statute. P sued D and lost in the courts below. The Court of Appeals of the District of Columbia held: 'We cannot regard the reproduction, through the agency of a phonograph, of the sounds of musical instruments playing the music composed and published by the complainants, as the copy or publication of the same within the meaning of the act. The ordinary signification of the words 'copying,' 'publishing,' etc., cannot be stretched to include it. The Supreme Court granted certiorari.