I saw Joni Mitchell live at the Blossom Music Festival center in Kent, Ohio.

I could say she was provoked;
a sopranino-voiced fan in the audience
punctuated the breaks between songs -- many breaks --
with a shrieking request for "Californiaaa!"

"Somebody help her," Mitchell chuckled at one point.
But the shrieks continued, until
Mitchell stopped cold and declared that it pissed her off.

The audience seemed genuinely startled -- I recall gasps and whispers.
And the people in whose company I attended
made more of Mitchell's criticism than
they made of the squeaky shrieky fan.

Oh, and the fan DID shut up after that.