[nayuki]

I agree with you and that's called a Dutch auction or descending price auction. https://en.wikipedia.org/wiki/Dutch_auction

But inevitably, someone (such as the vocal people in this thread) is going to complain that it means only the richest fans can afford to attend the concert. No duh, being rich means you are able to afford things that some others can't.

[banannaise]

One of the reasons that artists want their tickets to be accessible for less-wealthy fans is that those fans are often more invested. Expensive tickets lead to a lot of rich people who are there to be seen and to experience an exclusive event rather than people who are specifically interested in that artist.

You find similar effects at sporting events (which is part of why nearly every soccer club has a "supporters' section" with ticket prices deliberately kept very low).

[nayuki]

That's true. But there will still be some kind of rationing going on. If there are a thousand seats but a million fans, then 99.9% of them will be disappointed. Sure, you can lower the price, but then the winners will be either first-come-first-serve, or lottery, or nepotism.