George D. Beauchamp ( 1899 - 1941 ) was an inventor of musical instruments and co-founder of National Stringed Instrument Corporation and Rickenbacker .
George Delmetia Beauchamp ( March 18 , 1899 -- March 30 , 1941 ) was an inventor of musical instruments and a co-founder of National Stringed Instrument Corporation and Rickenbacker guitars .