Four-voice generative composer with 12 musical languages, harmonic sequencing, CV control and MIDI.

B.A.C.H. is a four-voice generative composer for Eurorack and MIDI.

It generates melodic, harmonic and rhythmic structures in real time. Its behaviour is shaped by the selected compositional language and by eight musical controls, each with its own CV input.

B.A.C.H. generates control signals rather than audio. Each voice provides GATE, PITCH and MOD outputs and can also be transmitted over MIDI.

Twelve compositional languages

• FUGUE constructs a polyphonic exposition from a subject, answers, a countersubject and episodes.
• CANON develops a leading line through imitation, transposition, delay, contrary motion, retrograde and augmentation.
• PROBA uses Markov chains to produce directed randomness.
• TINTINNABULI combines a melodic voice with voices derived from a triad or the current chord.
• MINIMAL applies gradual processes including phase shifting, addition, substitution and hocketing.
• CELLULAR turns the evolution of a cellular automaton into music, with access to 254 rules.
• TREE interprets L-systems and branching structures as melodic paths.
• FRACTAL uses recursive sequences and chaotic systems, including Thue–Morse, Fibonacci, Sierpiński and the logistic map.
• MOTIF develops chains of melodic and rhythmic cells drawn from 32 collections.
• HYBRID distributes several composition engines across the four voices.
• GROOVE organises four rhythmic roles using 64 structures.
• GROOVE MIX applies these rhythmic structures to pitches generated by an associated melodic language.

Eight musical controls

The eight encoders retain the same musical role across all twelve languages:

• MATERIAL selects the initial vocabulary or rule.
• MEMORY controls persistence and renewal.
• GROWTH shapes the development and length of the form.
• MORPH introduces rotations, inversions, shifts and mutations.
• DENSITY controls the number of events and active voices.
• TENSION moves the material away from its stable state.
• INTERACTION organises the relationships between the four voices.
• HUMANIZE adds performance gestures suited to each language.

Each control has a dedicated CV input with individually adjustable attenuation.

Musical and harmonic control

B.A.C.H. provides:

• 14 scales and a selectable root note;
• global note length and several velocity behaviours;
• ornaments and swing;
• 8 time signatures;
• form lengths of 1, 2, 4, 8, 16 or 32 bars;
• an INFINITE mode for continuous development.

The SEQUENCE page creates harmonic progressions of up to 64 positions. Each chord has its own relative root, quality, duration and inversion. VOICING automatically finds the shortest movement between the four voices.

The module includes 24 chord qualities, 96 factory progressions and 128 user locations on the SD card.

Breaks and live transformations

BREAK temporarily transforms the composition before returning to its underlying form.

Eight modes are available: AUTO, SILENCE, AGITATION, SUSPENSION, FRAGMENT, PULSE, EROSION and EXPANSION.

Breaks can last 1, 2, 4 or 8 bars. LIVE mode holds the transformation until the control is activated again.

CV and MIDI

Inputs:

• 8 attenuated CV inputs;
• dedicated CLOCK, PLAY/STOP, RESET and BREAK inputs.

Each of the four voices provides:

• GATE;
• PITCH, following the 1 V/oct standard over a 0–8 V range;
• MOD, with a 0–5 V range for dynamics and expression.

MIDI input accepts clock, transport commands, root-note changes and continuous controller messages. MIDI Learn simplifies controller assignment.

MIDI output transmits the four voices over independent or shared channels. It can also send transport commands, 24 PPQN clock and expression data.

The module can run from its internal clock, follow its CV clock input or synchronise to MIDI clock.

Presets and state recall

B.A.C.H. automatically restores its most recent state. The SD card provides 128 preset locations containing the complete composition, control, CV, MIDI, Break and harmonic progression settings.

https://www.kaona.fr/index.php/en/produits-3/bach