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@neauoire @bcgreen24 @npisanti @abowerman @MAKIO135 @jeluard
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If this is your first time trying out Orca, watch this introduction video. If you want to learn how to use a handful of basic operators, have a look at the workshop.



Pilot is a minimalist synth software designed to work via UDP, and to quickly get started with Orca. Have a look at pilot.orca to see how it should be used. This requires no setup, as long as both applications are open, they should be able to communicate with each other.

  • Launch Orca & Pilot.
  • In Orca, make sure that UDP is pointing to port 49161.
  • Bang something like ;03Cff to play a note.
  • Bang something like ;revff to add reverb.

Ableton Live

To send Midi notes to Ableton Live instruments, bang the Midi operator :, like :03C to send to Channel 1, Octave 3, Note C. Have a look at midi.orca to see it in action.

  • Launch Ableton Live.
  • Create a new midi instrument track.
  • Select IAC Driver(Bus 1)(OSX), or LoopMidi(Windows), in the instrument's inputs dropdown.
  • Activate the In toggle, on the instrument track.


To send OSC messages to SonicPi, select port 4559. SonicPi listens to the address defined in sync, to send to the live_loop, bang the OSC node =, like =a. Have a look at sonicpi.orca to see it in action. If you need help, visit the SonicPi x Orca forum.

live_loop :drum do
  sync "/osc/a"
  sample :bd_haus, rate: 1

Bitwig [Linux and JACK]

The following is taken from this page:

  • Quit Bitwig if running.
  • Start qjacktl.
  • Go to Setup > Settings > Parameters and set MIDI Driver to "none" (this turns off jack-midi)
  • Go to Setup > Misc and check "Enable ALSA Sequencer Support" (if not enabled)
  • Stop Jack if running and quit gjackctl
  • Run sudo modprobe snd_virmidi midi_devs=1 (to enable virtual midi with one device which is easier to understand for now)
  • Start qjacktl
  • Start jack
  • Open Connections: Connect device on left "0: QuNexus MIDI 1" (as an example) to "0:VirMIDI 5-0"
  • Open Bitwig
  • Under Options > Preferences > Controllers click "Add controller manually"
  • Choose "Generic MIDI Keyboard"
  • Once it appears as an input choose "Virtual Raw MIDI/1"


To send UDP messages to Dotgrid, select port 49160. To draw lines on Dotgrid, you need to bang the UDP node ; with different commands. Have a look at dotgrid.orca to see it in action.

  • ;0, clear layer #1.
  • ;0l1234, add a line from 1,2 to 3,4.
  • ;, redraw.

Here's a list of supported operations.

;0         // Clear Layer 1
;0l1234    // Add Line from 1,2 to 3,4
;0c1234    // Add Clockwise Arc from 1,2 to 3,4
;0r1234    // Add Reverse Arc from 1,2 to 3,4
;          // Redraw


Why does placement of V matter?

Orca operates linearly from the top-left, to the bottom-right, operators are executed in that sequence, and so the variables stored at the top, can be overwritten by the variables declared at the bottom.

Why is orca not making any sound?

Orca is not a synthetizer, it is meant to control audio & visual software, or hardware. Orca will never include domain specific operators to generate music or to create pictures. It is designed to be as generic as possible.



Will output the modulo of 6 % 4.



Will output uppercase C.



Will output lowercase C.



Will substract 8 - 3.


Not Null

Will bang if not null.

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