Possible Clues:

• One who might hit an 83-Down
• After work rushed in so as to see the entertainer
• Tony, e.g.
• Aida, for one
• Small work conducted by orchestra's lead singer
• Consequently, publicity man sent round article describing singer
• (Singer of) the highest vocal range
• So soft, Nora sounds so high
• Woman singing pointless stage work cuts second number
• Had no managerial duties when pursuing true power and a voice