Answer:
a public entertainment consisting of music and dancing often in masquerade.
One flat is F, since you can't go to the next -to-last flat. To find the name of a key signature with sharps, look at the sharp farthest to the right. The key signature is the note a half step above that last sharp. Key signatures can specify major or minor keys.
Hope that helps
Wagner, Richard Strauss, Gustav Mahler
