A surgical instrument system comprising: (a) an end effector operable to manipulate tissue, wherein the end effector comprises: (i) an ultrasonic blade, wherein the end effector is operable to apply ultrasonic energy at the blade, (ii) a clamp arm pivotable relative to the ultrasonic blade, and (iii) at least one electrode surface (150, 250, 252, 350, 352, 450, 452), wherein the at least one electrode surface (150, 250, 252, 350, 352, 450, 452) comprises a first electrode surface (150, 250, 350, 450), wherein the end effector is further operable to apply RF energy through the at least one electrode surface (150, 250, 252, 350, 352, 450, 452); (b) a generator operable to provide power to the end effector, wherein the generator is operable to drive the ultrasonic blade to apply ultrasonic energy, wherein the generator is further operable to drive the at least one electrode surface (150, 250, 252, 350, 352, 450, 452) to apply RF energy; (c) a first actuator operable to actuate the system to transect tissue with the end effector; (d) a second actuator operable to actuate the system to seal tissue with the end effector; (e) a controller in communication with the generator, wherein the controller is configured to sense the presence of tissue at the end effector, wherein the controller is configured to sense the position of the clamp arm relative to the ultrasonic blade, and wherein the controller is configured to select between one or both of ultrasonic energy or RF energy, and thereby control the generator to provide the selected one or both of ultrasonic energy or RF energy at the end effector, based on the sensed presence of tissue at the end effector, the sensed position of the clamp arm relative to the ultrasonic blade, and the actuation of the first actuator and/or the second actuator. (a) an end effector operable to manipulate tissue, wherein the end effector comprises: (i) an ultrasonic blade, wherein the end effector is operable to apply ultrasonic energy at the blade, (ii) a clamp arm pivotable relative to the ultrasonic blade, and (iii) at least one electrode surface (150, 250, 252, 350, 352, 450, 452), wherein the at least one electrode surface (150, 250, 252, 350, 352, 450, 452) comprises a first electrode surface (150, 250, 350, 450), wherein the end effector is further operable to apply RF energy through the at least one electrode surface (150, 250, 252, 350, 352, 450, 452); (i) an ultrasonic blade, wherein the end effector is operable to apply ultrasonic energy at the blade, (ii) a clamp arm pivotable relative to the ultrasonic blade, and (iii) at least one electrode surface (150, 250, 252, 350, 352, 450, 452), wherein the at least one electrode surface (150, 250, 252, 350, 352, 450, 452) comprises a first electrode surface (150, 250, 350, 450), wherein the end effector is further operable to apply RF energy through the at least one electrode surface (150, 250, 252, 350, 352, 450, 452); (b) a generator operable to provide power to the end effector, wherein the generator is operable to drive the ultrasonic blade to apply ultrasonic energy, wherein the generator is further operable to drive the at least one electrode surface (150, 250, 252, 350, 352, 450, 452) to apply RF energy; (c) a first actuator operable to actuate the system to transect tissue with the end effector; (d) a second actuator operable to actuate the system to seal tissue with the end effector; (e) a controller in communication with the generator, wherein the controller is configured to sense the presence of tissue at the end effector, wherein the controller is configured to sense the position of the clamp arm relative to the ultrasonic blade, and wherein the controller is configured to select between one or both of ultrasonic energy or RF energy, and thereby control the generator to provide the selected one or both of ultrasonic energy or RF energy at the end effector, based on the sensed presence of tissue at the end effector, the sensed position of the clamp arm relative to the ultrasonic blade, and the actuation of the first actuator and/or the second actuator.