Some of the week's highlights TODAY MUSIC FOR MOM Mother's Day concerts at Lewis Ginter Botanical Garden, Stony Point Fashion Park, Bon Air Presbyterian Church and Agecroft Hall. ALSO TODAY MUSEUM DISTRICT HOUSE TOUR Nine homes and gardens open in the Virginia Museum neighborhood. 257-9622, option 2. TONIGHT B.B. KING The blues master plays at Landmark Theater. 646-4213. FRIDAY, SATURDAY, MAY 19 ACE OF BASS Edgar Meyer and Mason Bates with the Richmond Symphony, various venues. 788-1212. SATURDAY-NEXT SUNDAY MINDS IN MOTION More than 1,400 area students dance at Arthur Ashe Jr. Athletic Center. 344-0906. NEXT SUNDAY BROAD APPETIT Celebration of food and art on Broad Street. 249-9123.