Systems (10) and methods (12) of controlling an ultrasonic surgical tool (20) with a console (22) are provided. A first drive signal (40) is applied to the ultrasonic surgical tool (20). A characteristic of a harmonic signal (44) resulting from application of the first drive signal (40) to the ultrasonic surgical tool (20) is acquired. A cancellation signal (70) is generated based on the characteristic of the harmonic signal (44). The first drive signal (40) and the cancellation signal (70) are combined to produce a second drive signal (80) that is sinusoidal. The second drive signal (80) is applied to the ultrasonic surgical tool (20) such that presence of the harmonic signal (44) resulting from application of the second drive signal (80) is reduced relative to presence of the harmonic signal (44) resulting from application of the first drive signal (40).