2009

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 will 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 will sound in
tune.
As electric pianos don’t have strings, this inharmonic relationship doesn’t apply to the
EVP88, nor the original instruments it emulates. The stretch feature was primarily included
for situations where you want to use the EVP88 in an arrangement alongside an acoustic
piano recording.
Using the Integrated EVP88 Effects
The EVP88 features built-in Equalizer, (Over)Drive, Phaser, Tremolo, and Chorus effects.
See these sections for details:
• Using the EVP88 Equalizer
• Using the EVP88 Drive Effect
• Using the EVP88 Phaser Effect
• Using the EVP88 Tremolo Effect
• Using the EVP88 Chorus Effect
208 Chapter 9 EVP88