A tuning device has a sound collecting unit having an input section for receiving a sound or vibration signal produced by a musical instrument and outputting a sound signal, and a wireless communication section for converting the sound signal into a wireless signal and transmitting the wireless signal to the outside. A computation display unit has a receiving section for receiving the wireless signal transmitted from the sound collecting unit and converting the wireless signal into a sound signal, a computing section that computes pitch information based on the sound signal, computes an amount of difference between the pitch information and reference pitch information corresponding to a reference sound name, and converts the computation result into a control signal for display, and a display section for acquiring the control signal and displaying information concerning the amount of difference computed by the computing section.