My son got an electricity set for Christmas that we have been playing with this afternoon. We made a simple DC circuit between a battery pack and a buzzer. I measured the voltage as 6 volts using a multimeter in parallel. We then decided to put a grape and a kiwi into the circuit. We got the following results: Grape: Lower pitch, 5.37v, 48.7 kohms (measured across the fruit) Kiwi: Higher pitch, 5.11v, 32.3 kohms I thought the pitch would be relative to the voltage, but it seems not. Given Ohms law I'm guessing pitch is relative to current? Anyone have an explanation? Thanks!