To provide a pitch shift device which is capable of suitably obtaining a pitch-shifted sound based on performance of an electronic stringed instrument such as a guitar or bass.

The pitch shift device is provided with choking detection means which detects choking of an electronic stringed instrument. When choking is detected by the choking detection means, control for interpolating the pitch shift change of a musical sound signal due to the change of pitch shift information read out from a pitch shift information group stored in pitch information storage means by pitch shift information readout means is performed by interpolating means of pitch shift control means. Therefore, unnatural pitch change of a pitch-shifted sound, which may occur when a pitch of pitch information of the musical sound signal of the electronic stringed instrument inputted from input means is shifted on the basis of pitch shift information read from the pitch shift information group, can be suppressed.