If you're a fan of live theater, book yourself some tickets for a play or other stage show at Bucharest Art Theatre. Look online for scheduling details.
You'll soon see why this Bucharest City-Centre arts and culture attraction is visited by many travelers. If you're searching for more to see and do here, Palace of the Parliament, Romanian Athenaeum, and Cismigiu Garden are in the area too. They won't take very long to reach from Bucharest Art Theatre.