Possible Clues:

• Traditional words before play interrupt each session
• Good luck playing Akela, bizarrely in production of 1984?
• *"Godspeed" to the cast of "Godspell," say
• *'Godspeed' to the cast of 'Godspell,' say
• It's good news for an actor to hear ___/It's bad news for an athlete to ___
• Encouragement to an actor, and what this puzzle’s starred answers do
• Superstitious words of encouragement, and a clue to 17-, 25-, 54- and 64-Across
• What you must do, to answer each pair of starred clues
• Stage whisper?
• Good luck to player from a supporter on holiday