Dr. Mortensen is a concert pianist, composer, and teacher. His interests at the piano include Schumann, Rachmaninoff, Bach, Argentinian tango composer Astor Piazzolla, and the jazz improvisations of Oscar Peterson. His students learn a natural and coordinated approach to piano technique, which prevents injury and allows for unprecedented freedom and facility at the keyboard. He also performs and teaches Irish and American roots music, playing mandolin, octave mandolin, Irish flute, Irish button accordion, five-string banjo, Uilleann pipes, and Irish whistle. He leads The Demerits, Cedarville University's premier roots ensemble, and created America's only college-level traditional Irish music session class.