Mass. Gen. Laws ch. 140 § 198
No proprietor, lessee or manager and no employee of a proprietor, lessee or manager of any public hall or room in which dancing is practiced, and for admission to which money or other valuable thing is accepted, shall admit, while dancing is practiced therein between six in the afternoon and six in the forenoon, any person fifteen years of age or under, unless such person is accompanied by a parent, guardian or adult member of the family with whom such person is residing; and any minor may be refused admission to or be excluded from any such hall or room while a dance is being carried on therein, unless such minor produces evidence satisfactory to the proprietor or his agent that he is over the age of fifteen years. This section shall not apply to a dance given by any charitable or religious society, or by any public or private school, or by any class, society or club the membership of which is restricted to some particular charitable or religious society or to some particular public or private school.
Mass. Gen. Laws ch. 140, § 198