Orca: Live Coding Music with an Esoteric Language
Orca is an esoteric programming language designed for live coding music. Developed by Hundred Rabbits (Devine Lu Linvega), it generates MIDI, OSC, or UDP sequences in real time from a grid of ASCII characters.
Principle: a Living Grid
Orca works like a cellular automaton: every character on a 2D grid is an operator that executes on each clock tick. Operators read their neighbours (left, right, above, below) and produce an output that can trigger other operators or send an audio signal.
1..D4..........
2..3...........
3..C...........
4..3*..........
5....M36.......
An Orca program looks like this: plain text, readable, editable live during a performance.
Core Operators
Orca distinguishes lowercase operators (passive, executed when they receive a bang) from uppercase operators (active, executed every tick).
| Operator | Role |
|---|---|
D | Delay — passes a bang every N ticks |
C | Clock — generates a cyclic counter from 0 to N |
A | Add — adds two values |
M | Multiply — multiplies two values |
R | Random — generates a random value within a range |
I | Increment — increments a value |
F | If — compares two values and sends a bang if equal |
: | MIDI — sends a MIDI note (channel, octave, note, velocity, length) |
; | UDP — sends a UDP message |
= | OSC — sends an OSC message |
A Concrete Example
Here is a simple sequence that plays a MIDI note every 4 ticks:
1D4..........
2.*..........
3.:03C4......
Step by step:
D4: delays the signal every 4 ticks → sends a bang.*: the bang activates the next operator.:03C4::sends a MIDI note — channel 0, octave 3, note C, velocity 4
Changing the 4 in D4 live instantly changes the tempo.
Why Orca?
Orca is not a conventional sequencer. Its strength comes from several aspects:
Radical minimalism — No complex GUI, no menus. Just a character grid and an editor. It runs in a terminal, in a browser, or as a standalone app.
Pure live coding — Every change is instant. You compose and perform at the same time. It is a full-fledged stage instrument, used in live coding performances.
Powerful despite its simplicity — Combining operators lets you build complex rhythmic, harmonic, and melodic patterns with very few characters.
Eco-conscious design — Hundred Rabbits develops their tools with digital sobriety in mind. Orca is lightweight, cross-platform, and runs on old hardware.
Installation and First Steps
Browser version
The fastest way to try Orca is the web version: hundredrabbits.github.io/Orca
No installation needed, runs directly in the browser. To hear sound, enable the built-in synthesizer (press *).
Desktop version (Electron)
1git clone https://github.com/hundredrabbits/Orca.git
2cd Orca
3npm install
4npm start
MIDI Connection
To control an external synthesizer or a DAW (Ableton, Reaper…):
- Create a virtual MIDI port (e.g. loopMIDI on Windows, IAC Driver on macOS)
- Select that port in Orca’s MIDI preferences
- Use the
:operator to send notes
The Community
Orca is open source (GitHub) and has an active community around live coding. Performances are regularly streamed on Twitch and YouTube, especially through the TOPLAP scene.
Good starting points to learn: the official wiki and the examples included in the repository.
Conclusion
Orca is a unique experience. Programming music with a 26-letter alphabet on an ASCII grid feels disorienting at first, but becomes incredibly expressive once you grasp the basics. If you want to explore the intersection of code and real-time music, Orca is an excellent starting point.