Here's a quick demo:
The eagle-eyed (or eared?) among you might notice a G7sus4 and a Bmin7b5 in there, as well as several chromatic passing chords. These chords aren't normally possible to get from the Scales & Chords device without automation, but by pre-programming different settings for each note, it works out!
To program settings, click the “SHOW DEVICES” button. Hold the desired note on your MIDI or on-screen keyboard and locate the corresponding CV8X4 device (labeled “C, D♭, etc.) Each knob adjusts the numbered parameters on the Combinator's front panel (each CV1 knob adjusts KEY for its note, each CV2 knob adjusts SCALE, etc.)
Adjust the knobs while holding a note and see the parameters on the above Scales & Chords device change to taste. Note that this instance of S&C is merely a display unit. The actual audio path is at the bottom of the Combinator stack. The bottom ID8 device is sounding the notes, and of course it can be replaced with any other Reason instrument.
The front-panel buttons can be used to quickly overwrite their indicated parameters for the whole program. The front-panel rotaries are automatically adjusted via the Combinator’s rear CV inputs, so manually adjusting them should best be avoided as it will offset the calibration. Voicer uses the mod wheel to trigger the “ALTER” button in S&C.
By default, chords are mapped to the C major key, with passing chords built on the chromatic notes in between. The default mapping includes a sus4 chord on G and a dim (m7b5) chord on B. The pitch wheel can be used to transpose the entire program +/- 12 semitones. In order to ensure all voicing functions are complete before notes are sounded, Voicer employs a 4ms lookahead function at the MIDI input.
Voicer requires 2 free rack extensions:
CV8X4 CV Generator from Aftermath Audio
ModSelsor CV Selector & Sensor from Hamu
Special thanks to the memory of Håkan Müller. His work made this whole idea possible.
EDIT: v1.1 Update
Thanks to ingenious feedback from Italophile and frm5993, I've made the following changes:
At the top of the stack, you'll find two new CV8X4 modules labeled "ROOT SHIFT A & B." These rotaries can be used to individually transpose the pitches of incoming chromatic notes +/- 12 semitones. This occurs *after* the "NOTE TRACKER" has detected the original pitch and passed the relevant preset to the Scales & Chords module, but *before* the notes are sounded. This means the user can program preset scales and played chords independently of each other. For example, the user can program any incoming D note to set the scale to D Phrygian, but play Cmin9 by turning the ROOT SHIFT for D down 2 semitones. This can be useful for getting more exotic chord progressions or progressions where various chords or scales are played over an ostinato bass. (Thanks frm5993!) Hold a note and watch the "TRANSPOSITION" module directly above the "DISPLAY" unit as you turn a ROOT SHIFT rotary. Note that this new routing uses the pitch wheel, so global transposition is now best accomplished by sending the player stack to a sequencer track and transposing the MIDI from there.
I've also included a variant of the patch entitled "VOICER 1.1 (KS) -TC." This version of the patch uses key-switches for the note presets. The "NOTE TRACKER" module will detect only played keys below C1. Holding a key in this range will not cause any notes to sound, but it will prepare the voicing functions. Playing any key C1 or above while holding a key-switch will voice a chord using that note as a root. This allows the user to create a series of multiple chords in one key, then change key by simply moving to another key-switch. (Thanks Italophile!) Playing any key C1 or above after releasing a key-switch will simply play that note. Try this for fun:
(1) Press and hold a key-switch to load your desired S&C settings
(2) Play a key above C1 to trigger a chord
(3) Release the key-switch, but continue to hold the chord note
(4) Solo over your sustained chord by playing a melodic line up top!
Here's the updated patch: