ORÁCULO

Generative harmonic instrument · 3.5" touch panel

Oráculo is not a sequencer that plays back what you program — it is an instrument that proposes its own harmony. You steer it (density, tension, mode, brain) and it dictates chords in real time, sounds them through its internal synthesizer, and sends them over MIDI to your rig. A harmonic companion that thinks outside your DAW.

1. The screen

Everything fits in a single view. The current chord rules the center; information lives in the corners.

Center — the live chord name (e.g. A min) and its notes (A · C · E). The rings

pulse with the beat; the orbs orbit (one per active voice).

STEP (top-left) — position in the 4-step visual cycle.
TEMPO (top-right) — BPM. In *slave* mode it shows the incoming external tempo.
Status line (top, center) — active MIDI, AUDIO, CLOCK and BRAIN.
DENSITY / BALANCE (bottom-left) — how many voices sound and their spread.
PLAY / STOP + vel (bottom-right) — transport and MIDI velocity.
Preset bank (bottom strip, 8 slots) — always visible.

2. Gestures

Oráculo is played with four gestures. The screen splits into two zones: the body (the whole circle) and the preset strip (bottom edge).

 ┌───────────────────────────────────────────┐
 │  STEP            status            TEMPO    │
 │                                             │
 │              ╭───────────╮                  │   BODY
 │              │           │   ← swipe ← →     │   tap        = play / stop
 │      swipe↑  │   CHORD   │   = prev / next   │   swipe ←→   = previous / next chord
 │      tempo+  │           │     chord         │   swipe ↑↓   = tempo ±5
 │      swipe↓  ╰───────────╯                  │   long-press = enter / exit EDIT
 │      tempo-                                  │
 │  DENSITY                          PLAY       │
 │ ┌─────┬─────┬─────┬─────┬─────┬─────┬──┬──┐ │   PRESET STRIP (bottom edge)
 │ │  1  │  2  │  3  │  4  │  5  │  6  │7 │8 │ │   tap        = load preset
 │ └─────┴─────┴─────┴─────┴─────┴─────┴──┴──┘ │   long-press = save preset
 └───────────────────────────────────────────┘

Gesture	In the body	In the preset strip
Tap	Play / Stop	Load that preset
Swipe ← / →	Previous / next chord	—
Swipe ↑ / ↓	Tempo +5 / −5 BPM	—
Long-press	Enter / exit EDIT	Save (overwrite) that preset

Tip: play is triggered by tapping the center of the chord. The preset strip is only the bottom edge.

3. Edit mode

A long-press on the body opens EDIT. The panel is organized into 5 pages; the dots at the top show which one you are on.

Tap = move to the next parameter on the page (the active one is marked with >).
Drag horizontally = adjust the active parameter (works for sliders and selectors

alike: the position picks the value).

Swipe ↑ / ↓ = change page.
Long-press = exit.

Page 1 · PERFORM — what you touch most while playing:

Parameter	What it does
DENSITY	Number of voices sounding (0–100%).
TENSION	Harmonic restlessness: more sevenths, ninth color and borrowed chords; less resolution.
BALANCE	Voice spread / weighting.
TEMPO	40–200 BPM.

Page 2 · ENGINE — how the engine behaves:

Parameter	What it does
MODE	Tonal · Modal · Markov (see §5).
BRAIN	Switches the harmonic brain (see §4).
TRANSPORT	Master · Slave · Internal (see §6).

Page 3 · KEY — tonality:

Parameter	What it does
ROOT	Tonic. `AUTO` = the brain's; pick a note (C…B) to lock the key (survives brain and preset changes).
SCALE	`AUTO` (the brain's scale) or one of 9: Maj, Min, Dor, Phr, Lyd, Mix, Loc, HMin (harmonic minor), MMin (melodic minor).

Page 4 · PHRASE — rhythm and register:

Parameter	What it does
RATE	Beats per chord: 1 · 2 · 4 · 8. The visual pulse stays per-beat; only the chord change slows down.
BASS	OFF / ON. Bass reinforcement (root −12) on the internal audio only; MIDI stays clean.
TRANSPOSE	Shifts everything: −24 · −12 · 0 · +12 semitones. Affects internal audio and MIDI. Does not change the harmony.

Page 5 · EXPRESS — dynamics and voicing:

Parameter	What it does
VOICE	Voicing: Close · Open · Wide (raises voices by octaves; same notes, harmony unchanged).
VELOCITY	Humanizes the attack: OFF · 4 · 8 · 14 of per-note variation (MIDI + audio).
RELEASE	Internal-audio tail: Short · Med · Long · Pad. Audio only.

The vertical axis does not adjust values: within a page everything is adjusted by dragging horizontally. The vertical swipe (↑ / ↓) changes the page.

4. Brains (BRAIN)

A brain is a rule set that defines the harmonic character. Oráculo ships 5, hot-swappable without cutting the sound: the current chord is kept and the change is heard on the next pulse. A flash confirms each switch.

To change it: EDIT → tap to the BRAIN target → drag horizontally.

Brain	Character	Default mode
default	Balanced, functional tonal.	tonal
ambient	Floating dorian, sevenths, soft cadences that don't resolve abruptly.	modal
jazz	Rich sevenths, marked ii–V–I progressions.	markov
dark_modal	Natural minor, melancholic, centered on minor degrees.	modal
minimal	Pure triads, direct I–IV–V, no ornaments.	tonal

Loading a brain also sets its default mode (but if you then load a preset, the mode saved in the preset wins).

5. The harmony engine

Oráculo generates, it does not repeat. Three levers shape the result:

TENSION — low = rest, triads, stable cadences. High = sevenths, borrowed color

(modal-interchange chords: minor iv, bVII, bVI) and less direct resolution.

MODE — *how* the next chord is chosen:

- Tonal — functional logic (tonic → predominant → dominant → tonic), biased by tension. - Modal — drifts by voice-leading proximity; more floating and modal. - Markov — the brain's transition weights (e.g. jazz's strong ii–V–I).

BRAIN + SCALE — each brain carries its scale. Oráculo derives chords by stacking

thirds *inside* that scale, so dark_modal is genuinely minor and ambient dorian, not a "major in disguise". On the KEY page you can lock root and scale by hand (ROOT/SCALE targets), which override the brain's until you return to AUTO.

6. Clock and MIDI

Oráculo sends chords over MIDI and syncs to a clock. The transport mode (the TRANSPORT target in edit) decides who leads:

Mode	Who leads the clock
Master	Oráculo leads: sends MIDI clock + start/stop to your rig.
Slave	Oráculo follows an external MIDI clock (shows the incoming BPM). If the clock is lost it freezes and holds the chord.
Internal	Runs free, without sending clock out.

Chords go out as MIDI notes at the shown velocity (vel).

7. Internal audio

Oráculo sounds on its own, through its internal synthesizer (a separate audio process so there are no clicks). Waveform (sine / triangle / saw) and volume are saved and recalled with presets. The output goes to your audio interface.

8. Presets

The bottom strip has 8 slots, always visible. Each stores a complete state: density, balance, tempo, tension, mode, transport, waveform, volume, brain and every setting on the KEY/PHRASE/EXPRESS pages (key and scale, rate, bass, transpose, voice, velocity and release).

Tap a slot → load that preset instantly (the active slot is highlighted).
Long-press a slot → save the current state there (overwrite, no confirmation; a

0.5 s flash confirms).

The label shows mode·tempo (e.g. ton·120). Presets survive reboots.

9. Power-on

Oráculo starts on its own when the Raspberry Pi powers up (automatic service). Nothing to launch: power it on and within seconds the main view appears, ready to play.

10. Quick cheat sheet

PLAY/STOP ............ tap the center
Prev/next chord ...... swipe ← / →
Tempo ±5 ............. swipe ↑ / ↓
Edit ................. long-press (center)  → tap cycles param · drag adjusts · swipe ↑↓ page
Change brain ......... EDIT → ENGINE → BRAIN → drag
Load preset .......... tap a bottom slot
Save preset .......... long-press a bottom slot

11. Troubleshooting

Tapping does not start playback → tap the center of the chord, not the bottom

edge (that strip is for presets).

The chord won't advance → are you in *Slave* with no external clock? Oráculo freezes

until it receives a clock. Switch to *Master* or *Internal* in EDIT → TRANSPORT.

No sound → check volume / waveform (loaded with a preset) and the connection to your

audio interface.

I want to step back one chord → swipe ← .

*Oráculo — generative harmonic instrument. Enjoy it.*