If your keyboard is producing notes that appear too low or too high in pitch, it's likely that the octave range of your Grandmother’s keyboard has been altered. To decrease the octave range by one octave at a time, press and hold the blue SHIFT button and then hit the green [ < KB ] button. To increase the octave range by one octave at a time, press and hold the blue SHIFT button and then press the green [ KB > ] button.