Very simple step sequencer

simplestepper

s.boot;

// set up the Synth
(
    SynthDef(\mainSynth, {
        arg attack=0.5,decay=0.5,sustain=0.5,release=0.5,gate=1,modulation_rate=1,depth=50,rate=100;
        var envelope,modulator,frequencyModCarrier,amplitudeModCarrier,ringModCarrier,signal,
        
        // -------- I've had to add a modulatorType argument to the synth - the way things were it'd be impossible to change
        modulatorType ; 

        envelope = EnvGen.ar(Env.adsr(attack, decay, sustain, release), gate); 

        modulator=BufRd.ar(1,modulatorBuffer,Phasor.ar(0,BufRateScale.kr(modulatorBuffer)*modulation_rate*buffTime,0,BufFrames.kr(modulatorBuffer)),1)*depth; 

        ringModCarrier = BufRd.ar(1, carrierBuffer, Phasor.ar(0, BufRateScale.kr(carrierBuffer) * 

        rate * buffTime, 0, BufFrames.kr(carrierBuffer)),1, 4) * modulator; 

        amplitudeModCarrier = BufRd.ar(1, carrierBuffer, Phasor.ar(0, BufRateScale.kr(carrierBuffer) * 

        rate * buffTime, 0, BufFrames.kr(carrierBuffer)),1, 4) *(modulator.unipolar); 

        frequencyModCarrier = BufRd.ar(1, carrierBuffer, Phasor.ar(0, BufRateScale.kr(carrierBuffer)*(modulator + rate)* buffTime, 0, BufFrames.kr(carrierBuffer)),1, 4); 


        signal = Select.ar(modulatorType, [ringModCarrier, amplitudeModCarrier, frequencyModCarrier]); 

        Out.ar(0, signal * envelope); 
    }).add; 
)

(
    // somewhere to store our sequence
    ~sequence = Array.fill(16, 0);

    // store a pointer to our synth
    ~synth = Synth(\mainSynth);

    // step through sequence
    Tdef(\sequencePlayer, {
        loop {
            16.do {
                arg i;

                // if step is on trigger synth, otherwise close synths gate
                if(~sequence[i] == 1) {
                    ~synth.set(\gate, 1);
                } {
                    ~synth.set(\gate, 0);
                };

                0.25.wait;    
            }
        }
    });

    // create a window
    ~window = Window("Sequencer", Rect(0, 0, 400, 40));

    // create a toggle button for each step -- we don't need these again so we don't store the array anywhere
    // and just add the buttons to the window
    Array.fill(16, {  
        arg i;

        Button(~window, Rect(i * 20, 0, 20, 30))
            // button has two states - one for on one for off
            .states_([
                ["O", Color.red, Color.black],
                ["X", Color.black, Color.red]
            ])

            // button has action that sets sequence value
            .action_({ |button|
                ~sequence[i] = button.value;
            })
    });

    // shows the window
    ~window.front;


    // start the sequencer
    Tdef(\sequencePlayer).play
)