frogprince, that doesn't make sense!

"Here's what Joni wrote:

Nobody stopped to hear him
Though he played so sweet and high
They knew he had never
Been on their T.V.
So they passed his music by
I meant to go over and ask for a song
Maybe put on a harmony
I heard his refrain
As the signal changed
He was playing real good for free

Clearly, Joni would NOT be influenced by the fact that the busker had not been on tv. She could hear that is music had great worth, so what is her reason for not stopping?