diff --git a/sclang-play/tut/ch03.sc b/sclang-play/tut/ch03.sc
index b98a688..9474bcb 100644
--- a/sclang-play/tut/ch03.sc
+++ b/sclang-play/tut/ch03.sc
@@ -202,3 +202,99 @@
 (
   a.set(\gate, 0);
 )
+
+(
+  SynthDef(\sine,
+    {
+      Out.ar(
+        0, SinOsc.ar(
+          Rand(440, 880), 0, 0.1
+        )
+      )
+    }
+  ).add;
+)
+
+(
+  Synth(\sine);
+)
+
+(
+  a = Synth(\sine);
+  a.writeDefFile("synth.out");
+)
+
+(
+  SynthDef(\sine, {
+    arg freq=440, amp=0.1;
+    Out.ar(
+      0,
+      SinOsc.ar(freq, 0, amp)
+    )
+  }).add;
+)
+
+(
+  Synth("sine");
+  Synth("sine", [\freq, 880])
+)
+
+(
+  a = Synth(\sine);
+  b = Synth(\sine, [\freq, 550]);
+  c = Synth(\sine, [\freq, 660, \amp, 0.5]);
+)
+
+(
+  c.set(\freq, 1000);
+  b.set(\amp, 0.3, \freq, 100);
+)
+
+(
+  a.free;
+  b.free;
+  c.free;
+)
+
+(
+  SynthDef(\hum, {
+    arg freq=440;
+    var finaloutput = Mix(
+      [
+        SinOsc.ar(freq, 0, 0.3),
+        SinOsc.ar(freq*2, 0, 0.2),
+        SinOsc.ar(freq*3, 0, 0.1),
+        SinOsc.ar(freq*3.33, 0, 0.01),
+        SinOsc.ar(freq*4, 0, 0.1),
+        SinOsc.ar(freq*4.5, 0, 0.01),
+        SinOsc.ar(freq*4.75, 0, 0.02)
+      ]
+    );
+    Out.ar(0, finaloutput);
+  }).add;
+)
+
+(
+  Synth(\hum, [\freq, 220]);
+)
+
+(
+  Synth(\hum, [\freq, 880]);
+)
+
+(
+  Synth(\hum, [\freq, 440]);
+)
+
+(
+  SynthDescLib.global.synthDescs[\sine].def.func.postcs
+)
+
+(
+  SynthDescLib.global.synthDescs.do { |desc|
+    if(desc.def.notNil) {
+      "\nSynthDef %\n".postf(desc.name.asCompileString);
+      desc.def.func.postcs;
+    };
+  }
+)