A question just occurred to me: does the phrase “traditional curtain raiser” get used AT ALL outside of a sporting context?

Actually I wondered if it even got used outside of the Community Shield context, but apparently it does – the Australian Grand Prix is a TCR, so is an MCC match at Lords.

It took until hit 35 on Google before a non-sporting traditional curtain was raised: hats off to the Malvern Spring Gardening Show, which is the traditional curtain raiser for the outdoor gardening show calendar, according to the Times.

What other non-sporting things have traditional curtain raisers? What should?