Joseph Leo

Older composer and music teacher Leo to fiery German female opera singer Armgart, From the short play Armgart. It was written by Victorian author George Eliot, pseudonym of Mary Anne Evans, and first appeared in the July 1871 MacMillan's Magazine.

It's unclear if "Leo" is his first or last name; no other is given.

Leo is also briefly mentioned in passing in George Eliot's 1876 novel Daniel Deronda as the Vienna music master of character Mirah Lapidoth, who tried to be a singer.