An accompaniment data generating apparatus has a phrase waveform data storing portion for storing sets of phrase waveform data each indicative of a phrase of accompaniment tones preformed at a reference tempo and each corresponding to a different reference note. The accompaniment data generating apparatus obtains a reproduction tempo, obtains the first reference note, selects a set of phrase waveform data corresponding to the second reference note whose tone pitch is different from a tone pitch of the first reference note, and reads out the selected phrase waveform data set at a speed by which the tone pitch of the second reference note of the selected phrase waveform data set agrees with the tone pitch of the first reference note of a case where a set of phrase waveform data corresponding to the first reference note is reproduced at the reference note.