
Vintage Clav Pitch parameters in MainStage
The Pitch parameters affect the tuning of the selected model.

Pitch parameters
Tune slider and field: Adjust tuning in one-cent intervals. At a value of 0 c (zero cents), the central A key is tuned to 440 Hz, or concert pitch.
Stretch Tuning slider and field: Use to deviate from the default equal-tempered scale by altering the bass and treble ends of the sound. This simulates the way stringed keyboard instruments such as pianos are tuned (see information below).
Note: Use of both Warmth and Stretch may result in a detuned sound that is quite similar to a heavy chorus effect. In some instances, this effect may be so extreme that Vintage Clav sounds out of tune with your project or concert.
Warmth slider and field: Set the amount of random deviation from an equal-tempered scale. High values add life to sounds. The Warmth parameter can be useful when you are emulating an instrument that has not been tuned for a while, or for slightly thickening a sound. When you are playing chords, the Warmth parameter creates a slight detuning or beating effect between notes.
Pitch Wheel slider and field: Determine the pitch bend range in semitone steps. Use your keyboard pitch bend wheel to control pitch bends.
Pitch Pressure slider and field: Adjust aftertouch sensitivity. On an original D6, applying pressure to a depressed key raises the pitch slightly. Pitch Pressure emulates this behavior. Values to the left of the center position lower the pitch slightly with aftertouch messages. Values to the right raise pitch.
Stretch tuning in acoustic instruments
The tones of upright pianos, and to a lesser extent grand pianos (due to their longer strings), have inharmonicities in their harmonic structure. This also applies to other stringed instruments, but it particularly affects pianos due to the length, density, and tension of the strings. If a piano is perfectly tuned to equal temperament across the keyboard range, the overtones of the low strings and the fundamentals of the high strings sound out of tune with each other.
To circumvent this problem, piano tuners use a technique known as stretch tuning, where the high and low registers of the piano are tuned higher and lower, respectively. This results in the harmonics of the low strings being in tune with the fundamental tones of the upper strings. In essence, pianos are intentionally “out of tune” (from equal temperament), so that the lower and upper registers sound in tune.
Because the original D6 is a stringed instrument, this inharmonic relationship also applies to Vintage Clav and the instruments it emulates. The stretch feature, however, was primarily included for situations where you want to use Vintage Clav alongside an acoustic piano recording or performance.