Possible Clues:

• "The Barber of Seville," e.g.
• Stage work, note, two companies accepted and a third is mounting
• Funny work from a cop involved with crime? Nothing in it
• One person who manages to be in a stupor in a musical show
• Gilbert and Sullivan genre (see letters 5 to 7)
• Light work sends one manager into a deep sleep!
• Funny conjuror grabs microphone before a show
• Patience, say, with which I manage resistance, having suffered head injury?
• Show magazine work to head of Etchings at Royal Academy
• Rossini's "Cinderella," e.g