curtain call

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The appearance of performers or a performer at the end of a performance to receive applause from the audience.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The moment at the end of a performance when actors come back on the stage and thank the audience for applauding them for their performance.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an appearance by actors or performers at the end of the concert or play in order to acknowledge the applause of the audience