Charles Sheffield Aka Mad Dog Was An Early-'60s R&B Singer From Lake Charles LA Noted For The Regional Hit "It's Your Voodoo Working " Which Is Acclaimed More Now Than When It Debuted On Excello Records In 1961. Sheffield Cut "It's Your Voodoo Working" At Crowley Studios Which Is Most Noted For Blues And R&B Recordings. He Wrote And Recorded 'Voodoo' Along With About Five Other Songs All Of Which Failed To Cause A Ripple He Then Soured On The Music Business And Disappeared From Sight.