In musical notation and performance, what frequency is commonly referred to as Middle C?

Okay, *that* was pretty trivial. Even my hubby, who works with frequencies and plays piano didn't know it.

You’ve 130 and 530 approx . The middle looks like about 260.

Gary, I had no idea but still found the question, and answer, interesting. I had never thought of musical notes having particular frequencies but then I'm as musical as a tin of custard.

RushMama2112, I just picked out the average one, middle number

corr'n: 11 other pitches.