There are many ways to prepare your child for his bar mitzvah—one of them is to make sure he knows how to get his groove on at the after-party. Imagination Stage, formerly known as BAPA (Bethesda Academy of Performing Arts), is offering hip-hop workshops to teach ’tweens and teens some moves they can use with confidence on the dance floor. Professional dancers teach a range of basic to advanced steps and combinations incorporating pop and lock, break dance, and freestyle. Kids in baggy pants, sequined leotards, or just plain ol’ T-shirts and shorts play games like “freezedance” and practice moving body parts in isolation before putting it all together Britney-style. Classes begin at 3 p.m. for grades 3 to 6 and at 4:30 p.m. for grades 7 to 10, at Imagination Stage, 4908 Auburn Ave., Bethesda. $15. (301) 280-1660. (Patricia Murret)