3

Chapter 3 ES2 44
Stretch tuning in ES2
The (coarse) Frequency knob of each oscillator enables you to tune oscillators 1, 2, and 3 in
semitones or octaves. The (ne tune) Frequency parameter enables you to ne-tune each
oscillator in cents (1/100th of a semitone). Precise detuning between oscillators can result in
beats, or phasing, between the oscillator frequencies. The higher the played frequency/pitch,
the faster the phasing beats. High notes, therefore, may seem to be somewhat out of tune in
comparison with lower notes.
CBD (Constant Beat Detuning) can be used as a corrective tool to even out the beating between
oscillators, or it can be used as a creative tool to emulate stretch tuning. The latter can be
particularly important when you use an ES2 sound alongside an acoustic piano recording. This is
because acoustic pianos are intentionally tuned “out-of-tune” (from equal temperament). This is
known as stretch tuning, and results in the upper and lower keyboard ranges being slightly out of
tune with the center octaves but harmonically “in-tune” with each other.
Choose a CBD value to detune the harmonics of low note frequencies in a ratio proportionate
with the fundamental tone of the upper note frequencies.
CBD oers ve values: o, 25%, 50%, 75%, and 100%. If you choose 100%, the phasing beats are
almost constant across the entire keyboard range. This value may, however, be too high, because
the lower notes might be overly detuned at the point where the phasing of the higher notes
feels right. Try lower CBD values in cases where the bass notes are a little too far out of tune with
the upper keyboard range.
The reference pitch for CBD is C3 (middle C): its (de)tuning is constant, regardless of the chosen
CBD value.