Celebrate the holiday season with the Cleveland Orchestra and Chorus as the groups perform music for the Christmas Season. There will be sing-a-longs, guest choruses and a surprise visit from a festive fellow dressed in red velvet. Performances take place at 7:30 tonight and tomorrow night at Severance Hall. Concerts repeat again at 2:30 and 7:30 p.m.on Saturday and Sunday. Tickets start at $45. (Niesel)