And the publisher, for the consideration aforesaid, hereby covenants and agrees, so far as it may be reasonably in his power, to protect the Æolian Company against any claim of any third person in respect to any and all copyrighted musical compositions which may be involved in this agreement, and the copyright of which may be owned by the publisher. And the Æolian Company, for and in consideration of the premises, hereby agrees that it will keep correct and true books of account in which it will set down or cause to be set down entries of all perforated music sheets made by it for playing the copyrighted musical compositions owned or controlled by the publisher; that it will on the 20th day of each and every January and July, during the continuance of the manufacture and sale by it of the perforated music sheets for playing such musical compositions, render unto the publisher a correct and true statement of the number, names, and other designations of such perforated music sheets sold by it during the six preceding calendar months, and that at the time of rendering each and every such statement it will well and truly pay unto the publisher a license fee or royalty of 10 per cent of the list prices made by the United States publishers of the printed scores or copies of such musical compositions, but never more than 50 cents for any one of such perforated music sheets. And the parties hereto mutually covenant and agree that nothing herein contained is to obligate the Æolian Company to pay any license fee or royalty upon such perforated music sheets as shall be made by it in the United States and sold or shipped to any other country, unless it shall have been decided by a court of competent jurisdiction of such other country that the copyright laws of that country shall be applicable to perforated music sheets of the kinds herein mentioned. And the parties hereto mutually agree and covenant that the term "perforated music sheets" is not to be construed as covering the controllers of those musical instruments which are generally known as phonographs, or music boxes, or hand organs. Anything herein to the contrary notwithstanding, at the expiration of thirty-five years from the payment of the first license fee hereinbefore provided, the Æolian Company shall not be entitled to licenses under the copyrights thereafter acquired by the publisher, but all licenses existing under copyrights theretofore acquired by him shall remain in force until the expiration of the terms of the copyrights under the terms hereinbefore provided.