Good Lord! There are sooo many things wrong with this bookcover. Clearly it is a cheap novelette of the sort The Third Man’s Holly Martens would write, but even so..
First up, we appear to have a guy in a hideous shirt who appears to attempting to drink a yard of ale through a Clarinet, as it is obvious he doesn’t know how to play it: His hands are the wrong way round for a start.
Then look at the pair on the table, he seems to be having a staring contest, while the woman appears to be trying to look over his shoulder and copy the crossword answers. There also appears that that there are two shuttlecocks on the table.
Then there is the title. What exactly is a Jazz Bum? Is it something to do with Wyatt Earp? I only ask because the font looks like it should be on a Wild West Wanted poster.