There may be some connection, but I cannot be sure. My Grandfather was born to a Barbara Hemmann, a niece to Carl Hemmann. His birth was in an apartment house on 56th St in NY on July 4, 1894. My Grandfather's name was Charles which in German is Carl.
Have you constructed much of a family tree? Do you know how I could let you have access to mine on Ancestry and vice versa.
Have you searched the records of early members of the Boston and New York orchestras? There is mention of a Carl Hemmann there. That Carl I am certain was my ggf's brother.
Also take a loook and search last name for best results http://www.fultonhistory.com/Fulton.html