He has sung operatic roles and concerts professionally in many theaters throughout the United States, singing with the: Cincinnati Opera, Atlanta Opera, Santa Fe Opera, Tri-Cities Opera (NY), Dayton Opera, Florida State Opera, Knoxville Symphony, Newton Symphony (MA), Tallahassee Symphony, LaGrange Symphony (GA), Cobb Symphony (GA), Northwest Florida Symphony, and more. Dr. Kirkpatrick is the inventor of a patented new method for teaching the lower laryngeal position in singing using electromyographic (EMG) biofeedback and is the architect of the BioGraph Infiniti voice training software suite available through the BFE-LFB online shop. He is the leader of the BFE-Voice International Research & Education Project team that receives financial support from the Biofeedback Federation CIC, a non-profit organization located in the United Kingdom.