The March 28, 1942 edition of Billboard included an article titled "The Marxian Approach to Bandleading" by Chico Marx. I've always thought of Groucho as the writer among the brothers. He wrote several books and articles, as well as many letters which have been compiled in books. As far as I know, Harpo, though adored by the literary types at the Algonquin Round Table, never did any writing. His autobiography, Harpo Speaks,was ghost written by Rowland Barber. The article in Billboard is the first piece of writing I've seen carrying Chico's byline. Whether he actually wrote it himself, I don't know.
The article was written three months after Chico left the brothers' act to lead a band. Among other things, he writes:
The first thing I do when a poor but ambitious youngster comes to me and reverently beseeches some inside info on how to become a maestro is give him Toscanini's telephone number. After that I look myself square in the eye--which is no mean trick when you haven't got a mirror on you--and ask myself the burning question, "Marx, how the hell did you get into the band business?" Even tho this is where you came in, don't go away yet. Tea and cookies will be served later.Pretty good stuff, I'd say. To read the whole article, click on the link in the first sentence in of this post.