Abstract: A visual indicator of temporal accuracy of compared percussive transient signals having a receiver for a reference input signal, a receiver for a performance or test input signal. An electronic circuit determines whether the first signal received is received by the reference input signal receiver or the performance input signal receiver. Further, the circuit determines the time difference between when the reference signal and the performance signals are received. A visual display indicates to the user whether the test signal is ahead or behind the reference signal and by how much it is ahead or behind. The indicator further displays an indication of when the two signals are received at substantially the same time.