The HR-2 Harmonizer lets you create one or two voices of harmony when playing single note passages. You have 2 different voices which you can select what steps you want them to create harmonies in (up to an octave up or down on each voice). You can also select the key that you are playing in, and it creates an instant harmony with your playing. Separate controls for each voice (level control and pitch control). The HR-2 does 1 and 2 part harmonies in any interval in the following keys: Am, Bm, Cm, Dm, Em, Fm, Gm, A, B, C, D, G, F. The HR-2 was discontinued 1999, but the Harmonist effect lives on in the new PS-5.