"I could hear a roll of muffled drums" (1.1.), says our narrator. Thank you, thank you.
But the drumroll isn't to introduce an entertainer. It's to introduce the Duke of Buckinghamshire, who is to be executed.
Actually, this could be considered entertainment in the 16th century.
What's the Duke's crime? Saying that the king "would likely die without a son to succeed him on the throne" (1.3).
In other words, the Duke's crime is speaking the truth.
Our narrator, Mary Boleyn, is the Duke's niece, and she expects the king to step in and pardon him before the executioner's axe falls.
When her uncle's head bounces into a nearby haystack, Mary realizes she was wrong.
Mary's mother tells her she was stupid for thinking her Uncle might be pardoned. "There is no room for mistakes at court" (1.12), she warns her daughter. Make a mistake and heads will roll.