Section 71. For the purpose of promoting the usefulness of public school property the school committee of any town may conduct such educational and recreational activities in or upon school property under its control, and, subject to such regulations as it may establish, and, consistently and without interference with the use of the premises for school purposes, shall allow the use thereof by individuals and associations for such educational, recreational, social, civic, philanthropic and like purposes as it deems for the interest of the community. The affiliation of any such association with a religious organization shall not disqualify such association from being allowed such a use for such a purpose. The use of such property as a place of assemblage for citizens to hear candidates for public office shall be considered a civic purpose within the meaning of this section. A school committee shall award concessions for food at any field under its control only to the highest responsible bidder. This section shall not apply to Boston.