Pro Co Sound is a Michigan Corporation founded by Charlie Wicks in 1974. Pro Co builds audio cables and related products for Musical Instrument retailers (stores, catalog retailers and distributors) and Sound Contractors.

The founders of GHS had a wealth of string making experience when they started the small family-owned business in 1964. Now, GHS has grown to one of the leading manufacturers in this music specialty. The "Brightness Bar" found on select packages of strings, will show you what strings produce which kinds of tone.