Playing deliberately obnoxious music to a captive audience? Yeah that's a CIA torture technique. Unironically.
I think it's a fine idea for a fundraiser.
When I was in middle school, we had an annual fundraiser for the American Heart Assoc. It was one of those "____-a-thon" style events where we all had to jump rope for as long as we could, and we gathered pledges from family members ("only 1¢ per jump, Aunt Sally!"). But this was only for an hour, and it replaced our normal PE period, so it wasn't a diversion from the normal course of schooling. And not everyone participated.
That's the kind of thing I had in mind when writing that comment, but now I'm realizing the parent comment was talking about the entire student body, for the entire school day.
I agree with you. My original take was hot... and bad. :)