The fat man was explaining to the woman that money was a liquid, and that the health of the economy could be measured by how fast the liquid flowed through all the different parts. He said that if you gave a hundred plastic dollars to a rich man and a hundred plastic dollars to a poor man, the rich man's plastic dollars would be like drops in a reservoir, and they would move a lot slower than the poor man's dollars. The poor man's money would be like drops in a river. They would flow a lot faster and farther than the rich man's money.
The dark-haired woman said that the rich man's money worked just as hard as the poor man's --- invesments created jobs. But the fat man argued that rich dollars just flowed from one financial reservoir to another, without ever going through the rest of the economy. The poor man's dollars are more liquid than the rich man's, so funding the flow-through ---paying people to consume---was good for the economy, because poor people bought things, and that created jobs for everybody.
then, further into the book, this one:
Jazz isn't music. Jazz is what happens when the music disappears and all that's left is the sound and the emotion connected to it. Jazz is a scream or a rant or a sigh. Or whatever else is inside, trying to get out.