I just re-watched his simulated "pep-talk" for the UM team. It hit me that no one under 30 understood his line "your wife ran off with a drummer." To Lou, who is my age, a "drummer" is a traveling salesman, not a bongo banger...
Have not heard that in over 35 years.
Drummers were traveling salesmen who worked at first for large New York and Philadelphia wholesale houses.
My Grandmother would often call traveling salesmen, Drummers.
http://www.drbilllong.com/2006Words/Drummer.html
Drummers
Drummers were traveling salesmen who worked at first for large New York and Philadelphia wholesale houses. As Friedman says, "They carried dry goods, whiskey, groceries, patent medicines, jewelry, chemicals, hardware, and leather goods" (Birth of a Salesman, 57). But the name drummer was, if not a derogatory term, at least not reflective of the image that merchants wanted to create for their traveling salesmen. The first appearance of "drummer" to connote a commercial salesman was, according to the OED, in 1827: "The Nos. of Lodge's book..were left by some drummer of the trade upon speculation." The word had made it across the sea by 1860, however, since John Bartlett, in his Dictionary of Americanisms, defined drummer as "a person employed by city houses to solicit the custom of country merchants." By 1882, they were so common throughtout the land that one could say "As enterprising as a Chicago drummer." Of course, the word referred to their enterprising, energetic, and possibly annoying tendency to "beat the drum" for whatever product they were selling.