Sonic Pi and hydra.ojack communicating via midi and audio See it on https://youtu.be/Du0yLoDYHOs

Hydra Sketch2

//Sonic Pi controlled code using midi and audio input by Robin Newman
// register WebMIDI
navigator.requestMIDIAccess()
    .then(onMIDISuccess, onMIDIFailure);

function onMIDISuccess(midiAccess) {
    console.log(midiAccess);
    var inputs = midiAccess.inputs;
    var outputs = midiAccess.outputs;
    for (var input of midiAccess.inputs.values()){
        input.onmidimessage = getMIDIMessage;
    }
}

function onMIDIFailure() {
    console.log('Could not access your MIDI devices.');
}

//create an array to hold our cc values and init to a normalized value
var cc=Array(128).fill(0.5)

getMIDIMessage = function(midiMessage) {
    var arr = midiMessage.data    
    var index = arr[1]
    //console.log('Midi received on cc#' + index + ' value:' + arr[2])    // uncomment to monitor incoming Midi
    //var val = (arr[2]+1)/128.0  // normalize CC values to 0.0 - 1.0
    var val = arr[2]
    cc[index]=val
}

//cc[0] controls kaleid, cc[1]-cc[3] control rgb solid mask, cc[4] controls masks alpha: can blank the screen.
//audio controls colour out of voronoi
voronoi(3,0.3,-0.3).color(()=>a.fft[0]*3,0.9,-0.7)

  .scale(0.3,1)
  .kaleid(()=>cc[0])
  .luma(-0.8)
  .colorama(0.05,-0.6)
  .mult(solid(()=> cc[1],()=> cc[2],()=> cc[3],()=> cc[4]))
  .out(o0)

SonicPiCode.rb

#sonic pi code by Robin Newman, Dec 31 2022
#drives sketch on hydra.ojack.xyz running on Chrome browser
#requires Sonic Pi audio output looped back to Chrome browser
use_midi_defaults channel: 1,port: "iac_driver_bus"
set :kill,false
midi_cc 4,1
comment do #uncomment to stop Bass note will take time to die away
  midi_cc 4,0
  set :kill,true
end
use_midi_logging false
use_debug false
sf=2

live_loop :mid0 do
  stop if get(:kill)
  midi_cc 0, [3,6,9,5,10,15].tick # sends to control 0 a random integer between 3 and 6
  sleep 0.125*sf
end
live_loop :mid1 do
  stop if get(:kill)
  midi_cc 1,[0,1].tick
  sleep 0.125*sf #rates of change of r,g,b cc all different
end
live_loop :mid2 do
  stop if get(:kill)
  midi_cc 2,[0,1,].tick
  sleep 0.25*sf
end
live_loop :mid3 do
  stop if get(:kill)
  midi_cc 3,[1,0,0,0,1,1,1,1].tick #mask out possibility of r,g,b cc all 0
  sleep 0.5*sf
end

with_fx :reverb,room: 0.7,mix: 0.7 do
  live_loop :aud do
    stop if get(:kill)
    if tick%64 == 0
      use_transpose [0,5,7,-5].tick(:tr)
      if look(:tr)==4
        set :kill,true
        midi_cc 4,0
      end
      synth :fm,note: (octs :e2,3),sustain: 10*0.125*sf,release: 64*0.125*sf,amp: 2
    end
    
    density dice(2) do
      use_synth :tb303
      k=play scale(:e2,:minor_pentatonic,num_octaves: 2).choose,release: 0.125*sf*2,cutoff: rrand_i(70,110)
      control k,cutoff: 100,cut_off_slide: 0.125*sf*2
    end
    sleep [0.125*sf,0.25*sf].choose
  end
end