Possible Clues:

• Mocking son, very cold about a sister at first
• Cutting — snide
• Artist's taken aback by troupe in concert, initially mocking
• Like 'Yeah, that'll ever happen'
• Cutting rotten carcass with it
• Biting, as at a roast
• Using scornful language, artist's upset by actors in charge
• Bitter racist as horrible Conservative
• Mocking all the actors in Indian dress heading for curtain-up
• Barbed, in a way