A surgical system comprising: a power supply; a connector coupled to the power supply, wherein the connector comprises a first wire and a second wire; and a surgical instrument coupled to the connector, the surgical instrument comprising: a body assembly including a trigger, a transmission assembly extending distally from the body assembly, the transmission assembly comprising a waveguide and a blade at a distal end of the waveguide, a transducer disposed in the body assembly and coupleable to the waveguide, the transducer comprising: a first electrode, a second electrode, and a transducer element in communication with the first and second electrodes, wherein the first electrode, the second electrode, and the transducer element are rotatable relative to the body assembly, and a connection assembly operable to selectively electrically couple the first wire to the first electrode and the second wire to the second electrode; characterised in that the connection assembly comprises a solenoid and an extensible member, wherein the solenoid is operable to extend the extensible member to contact the first electrode or the second electrode, and wherein the extensible member is electrically coupled to the first wire or the second wire. a power supply; a connector coupled to the power supply, wherein the connector comprises a first wire and a second wire; and a surgical instrument coupled to the connector, the surgical instrument comprising: a body assembly including a trigger, a transmission assembly extending distally from the body assembly, the transmission assembly comprising a waveguide and a blade at a distal end of the waveguide, a transducer disposed in the body assembly and coupleable to the waveguide, the transducer comprising: a first electrode, a second electrode, and a transducer element in communication with the first and second electrodes, wherein the first electrode, the second electrode, and the transducer element are rotatable relative to the body assembly, and a connection assembly operable to selectively electrically couple the first wire to the first electrode and the second wire to the second electrode; characterised in that the connection assembly comprises a solenoid and an extensible member, wherein the solenoid is operable to extend the extensible member to contact the first electrode or the second electrode, and wherein the extensible member is electrically coupled to the first wire or the second wire. a body assembly including a trigger, a transmission assembly extending distally from the body assembly, the transmission assembly comprising a waveguide and a blade at a distal end of the waveguide, a transducer disposed in the body assembly and coupleable to the waveguide, the transducer comprising: a first electrode, a second electrode, and a transducer element in communication with the first and second electrodes, wherein the first electrode, the second electrode, and the transducer element are rotatable relative to the body assembly, and a connection assembly operable to selectively electrically couple the first wire to the first electrode and the second wire to the second electrode; characterised in that the connection assembly comprises a solenoid and an extensible member, wherein the solenoid is operable to extend the extensible member to contact the first electrode or the second electrode, and wherein the extensible member is electrically coupled to the first wire or the second wire. a first electrode, a second electrode, and a transducer element in communication with the first and second electrodes, wherein the first electrode, the second electrode, and the transducer element are rotatable relative to the body assembly, and