posted 10 September 2000 12:26            

AutoCord.KYM

Those of you who have received Kyma5 may have seen a module in the prototypes called Pete's Autochord. This was limited to
major chords only. Well, attached is a full function version with major and minor key signatures. The autochord is an early stage
attempt to allow me to perform the whole of the Hallelujah chorus totally live and and totally on my own.

How to operate the new auto chord

You must have a MIDI keyboard attached and a live mic.

First press a single key on the keyboard and then press "set major" or "set minor key" on the virtual control surface. The key
signature has now been set. You don't need to touch the virtual control surface again unless you want to transpose to another key
signature.

On the keyboard, play a simplified bass line while singing into the mic. The new autochord will decide whether the chord should be
major or minor by looking at the bass note you are playing and knowing the key you are in. It then listens to the note you are singing
and automatically pitch-shifts your voice to make two additional voices singing in harmony with your own voice. The new notes are
based on the chord suggested by the last note played on the keyboard, so it's best to play only one note at a time and to be as minimal
as possible. Even if you don't touch the keyboard the autochord still makes guesses at the best harmonies just by listening to your
voice. Also the mic input must be a single sound otherwise the autochord gets very confused. Quite often just a single harmony is
better so you can turn down the third or the fifth, and change their octaves so that they can be above or below the note you are
singing. Also it works better with headphones or a pre-recorded vocal track as the new harmony can feed back into the live mic and
cause the autochord to track in an odd way.

History of the Autochord

I'd always been interested in vocal harmony but as we only have one voice, it's hard to do it live unless you have a bunch of mates.
When harmonizers first came out, it meant you could produce harmonies as you were singing, but they were limited to fixed intervals
which only sounded good on a very limited number of songs. You could of course keep rotating the pitch knob to different intervals
as you were singing but this wasn't very intuitive and caused quick jumps and was really limited to only one harmony.

Even later when the interval could be controlled by MIDI it still meant that you had to play the interval and not the note you wanted to
hear. So you would
have to subtract in your mind the note you were singing from the note you wanted to hear as a harmony and play that.

Then Kyma had the monotonizer which could be adjusted and made polyphonic so that by playing a chord on the keyboard, you
could sing any note but the chord sound of your voice remained true. This was well and good but it did mean that you had to move
your fingers abruptly or use the sustain pedal. It was hard to avoid the sound of voices cutting off. Also if you slurred notes the
harmonies would not slur with you.

Now with the auto chord you can slur notes and the harmonies move but they do occasionally jump when the notes move to a
different interval. Also even if your one finger keyboard timing is poor, most of the time the chosen notes are the same so that
jumping is kept to a minimum.

I may make a version that gradually changes as the intervals change. I wonder if any one would find this interesting.

Please feel free to use this module as you wish but if you do end up
using it on an album I wouldn't mind a credit.

regards Pete Johnston.