P was a coop housing corporation. Ds are shareholder tenants of P. The board of directors adopted a rule and regulation that prohibited the playing of musical instruments before 10 in the morning and after 8 in the evening and that playing instruments in excess of 1.5 hours per day was prohibited. Ds had two daughters who are musical artists. They needed to practice for 3.5 hours per day and did so until the new rules were instituted.