Week4 - SuperCollider - GUI

Here is my GUI code. It is not completely functional. The code works and a GUI window comes up. However, I think there is an issue with my SynthDef, as no sound is produced (yet). I have successfully achieved sound with a window when I created a simple SinOsc SynthDef. I think everyone has heard the sound of a sine wave moving up and down so I wont provide a soundfile of that.

(
//Global Variables
~thisPath =     (PathName.new(Document.current.path)).pathOnly;

 //Granular Synth
 SynthDef(
 \GranS,

 {
 //Arguments
 arg    granDens    =    0,        //trigger, start at 0
     granRate    =    1.0,    //Values: 0.5, 1.0, 2.0, -1.0
     granPos        =    0,
     granDur        =    0.2,
     granPan        =    0,
     granAmp        =    0.5,
     bufNum        =    0;

 //Variables
 var    bufid,
     bufNum1,
     signal,
     trig;    

 //Buffer SF
 bufid    =    Buffer.read(s, ~thisPath++"Wonder.aiff");
 bufNum1    =    bufid.bufnum;

 //Setup
 trig    =    Impulse.kr(granDens);

 //Signal Granulate
 signal    =    TGrains.ar(
                     numChannels:    2,
                     trigger:        trig,
                     bufnum:            bufNum,
                     rate:            granRate,
                     centerPos:        granPos,
                     dur:            granDur,
                     pan:            granPan,
                     amp:            granAmp,
                     interp:            2);                    
             
 //Output Signal
 Out.ar(0, [signal]);
 }
 ).send(s);
 )

(
//GUI Window

//Variables
var    win,
 slid,
 syn,
 sliderData;

//My window
win    =    SCWindow(
         name:    "GUI for CC",
         bounds:    Rect(
                     left:        600,
                     top:        750,
                     width:    400,
                     height:    200));
syn    =    Synth(\GranS);                    
                 
//Setup Window
 win.front;
 win.view.decorator    =    FlowLayout(win.view.bounds);
 //win.view.background    =    Color.black;                                

//Slider for my Window
 slid    =    EZSlider(
             window:        win,
             dimensions:    300 @ 25,
             label:        "granDens",
             controlSpec:    ControlSpec(
                             minval:    0,
                             maxval:    10,
                             warp:    \lin,
                             step:        1,
                             default:    1),
             action:        {    |edz|syn.set(\granDens, edz.value)},            
             labelWidth:    60,
             numberWidth:    40);                                            
)