If you are searching for American composer William Copper, you found his publisher's site
at The Hartenshield Group, Inc. .
Other spellings include William Cooper, William P. Copper, William P. Cooper, Will Copper, Will Cooper, Wil Copper, Wil Cooper, Pete Copper, Bill Copper, Bill Cooper, and so on. But composer William Copper (born 1953, Lyndhurst, VA) is NOT the same person as conspiracy-theorist William Milton Cooper, whose name is sometimes misspelled as Copper.
The composer's uncle was Bill Copper of Matawan, NJ (William F. Copper, [1911-1997]), his father John M. Copper [1902-1982] of Lyndhurst, VA, his grandfather W. G. Copper of Lyndhurst, VA (William George Copper [1875-1959]) and great-great-great-great?-grandfather William Copper (1702-1759) lived and died in Kent County, Maryland.
Please see biographical information at http://www.hartenshield.com/william_copper.html for publisher's bio, photo, and selected works.