To give a quick reply to Paul Eggert, you can find information about
Gallagher and Shean (that's the correct spelling) at the link below.
Al Shean was born as Al Schonberg (with an umlaut over the o; an umlaut
is a pair of dots over a letter -- it looks just like a Themodist
hole!) and it is pronounced something like Shirn-berg.

Al's sister Minnie was married to a guy named Sam, and they had five
children, all boys.  Their names were Leonard, Adolph, Julius, Milton
and Herbert.  The oldest three went into vaudeville, and after becoming
moderately successful, they changed their names to Chico, Harpo and
Groucho.  I am not sure what happened to them after that(!).

  http://members.rogers.com/vaudeville/vaudgs.htm

Randolph Herr