Hi. The 12th octave is a more "musical" e.q. setting than the frequency based FFT. A 12th octave means you are seeing all 12 semi-tones of the "chromatic scale" octave. The higher peaks will be the fundamental (or the played notes) with other peaks occurring due to the overtone series (3rd, 5th, octave, etc). This is why you see the keyboard mapping below the spectral output. Please refer to page 261 of the Studio One v5 manual for more information about the 12th octave scale. A reasonable amount of music theory will help you more with the 12th octave system.