Any city having a population of more than 75,000 and owning a city auditorium, civic center, coliseum, convention hall, stadium, theater, exhibition hall or combination thereof or other place of public assembly, may, in order to further the best interest of the public and lead to greater use of any such facilities, do all things necessary and proper to encourage the use thereof by arranging or engaging shows, plays, exhibitions, performances and all other entertainments of whatsoever nature, except motion pictures produced expressly for commercial exhibition, exclusively of a motion picture shown as a part of and related to a live program or a show, or a motion picture which has been generally removed from commercial exhibition in motion picture theaters, or a motion picture which is not shown or exhibited in such place more than twice and then only on one day, and exclusive of travelogues, educational or trade show films which are exhibited by educational, civic, trade, or religious organizations, to view which no admission fee is charged or the net proceeds of any admission fee charged are fully utilized for educational, religious or charitable purposes. Such encouragement may, without limitations as to other permissible activities, include the expenditure of city funds to promote such activities and to bring notice to the public of entertainments at such public facilities, engaging persons to bring entertainments thereto from which the city may derive income, and the payment of funds to such persons in advance or out of proceeds derived therefrom for payment therewith; and may include entering into agreements with such other persons guaranteeing minimum sums to be payable to such persons for future performances provided that at no time shall the aggregate amount of all outstanding guarantees be more than such sums as may be fixed by the governing body of such city. Notwithstanding any provision of any city charter, the council of any such city may appropriate funds to a special or revolving account in order to engage, advertise and promote any such entertainment and to operate any of the foregoing facilities, and when such fund is created such person or persons as may be designated by ordinance of such governing body, after providing fidelity bond with corporate surety payable to the city in a penalty not less than the authorized amount of such special or revolving fund, may sign checks against said fund and expend cash therefrom for any of the foregoing purposes.