Ballet and Flamenco Classes, 1431 Beacon Street. The Brookline Ballet School opened on January 11.  The school offers youth and adult ballet, as well as other dance and exercise classes for preschoolers, youth, and adults of all ages and abilities.  Teh school offers classes in Flamenco for both beginners and experienced dancers on Thursday afternoons. For details, go to www.brooklineballet.com, call 617.879.9988, or drop by the studio.