In one embodiment, a surgical instrument comprises an articulable harmonic waveguide. The articulable harmonic waveguide comprises a first drive section comprising a proximal end and a distal end. The proximal end of the first drive section may be configured to connect to an ultrasonic transducer. The articulable harmonic waveguide further comprises a first flexible waveguide coupled to the distal end of the first drive section. An end effector extends distally from the first flexible waveguide. The surgical instrument further comprises an articulation actuator to flex the first flexible waveguide.