FOF Choir

A choir built from formant and granular synthesis...

The story

I came across a CD-ROM with Csound files, containing a choir imitation using granular synthesis, which I used more than 15 years ago in a project. Csound is a powerful sound and music programming system. Csound’s FOF opcode produces sinusoid bursts useful for formant and granular synthesisis, loosely based on IRCAM’s CHANT program. Each FOF produces a single formant, and the summed output of four (or more) produces a vowel imitation.

The FOF Choir – Basic – instrument produces the 5 vowels (a, e, i o, u) which can also be used in a random fashion.

The FOF Choir – Vowel Morphing – instrument produces slow morphing textures, each note has its own permutation of 4 vowels. There are two round-robins for each note, to obtain a even more less-repeating texture.

Both instruments are available in Kontakt 6 and in DecentSampler format (split into 7 instruments: 5 individual vowels, random vowel, vowel morphing)
Developed in CSound 6.15, Kontakt 6, DecentSampler
Demo to get an impression:


Leave a review to let others know what you thought of the instrument!

  • Perfect retro synth choir...

    Not much needs to be said about this library other than that it is a marvelous creation. It works very nicely in both the Kontakt and DS versions and has a very usable interface. The sounds are great and fit perfect with electronic or otherwise non-traditional scores, especially when run through some basic reverbs and delays. I definitely recommend giving this library a try!

    christopher13 October 2021
  • Classic Compu-Choir

    This has that quintessential 90's computer voice sound and I love it! It's a little limited, and you need to load a separate instrument to get the vowel morphing. The GUI is cool, but takes a little experimentation to figure out. Also, I noticed it clips pretty easily, so might require backing off the main output level. Make sure you check out FOF Choir Matrix!

    ChesterGwazda13 October 2021