This just aired on National Public Radio (NPR): Lester Young: 'The Prez' Still Rules At 100 by Tom Vitale. "August 27, 2009 - In the 1930s, Lester Young - known as the 'President of Jazz' or simply 'The Prez' - led a revolution on the tenor saxophone that influenced generations to follow..Young also had a flair for language: He said he had 'big eyes' for the things he liked, he nicknamed Billie Holiday 'Lady Day,' and he called women's feet in open-toed shoes 'nice biscuits.' He also made up new words that found their way into songs. Young's cachet among hipsters led to his popularizing now-common words. Everyone started using the word 'cool' after they heard him say it, according to jazz historian Phil Schaap. 'But the one that really makes the most sense,' Schaap says, 'you call up Lester Young for a gig, he'd say, 'Okay, how does the bread smell?' So he used 'bread' for money for the first time.'." http://www.npr.org/templates/story/story.php?storyId=112255870
One reference dates "bread" as money back to 1935 and says it was originally criminal slang. Suggested by "dough," mid 20th century. "20th Century Words: The Story of New Words in English Over the Last 100 Years" by John Ayto (Oxford University Press, New York, 1999). Page 196. Cool has a long history - see https://www.phrases.org.uk/bulletin_board/49/messages/1137.html But it "caught on" in the 1950s and 60s. So Mr. Young may have popularized it.