diff --git a/sclang-play/tut/ch02.sc b/sclang-play/tut/ch02.sc
index bc52379..6c0c844 100644
--- a/sclang-play/tut/ch02.sc
+++ b/sclang-play/tut/ch02.sc
@@ -424,3 +424,73 @@
 
   w.front;
 )
+
+// 2.5
+
+(
+  {
+    Mix(Saw.ar([440, 443, 437], 0.1))
+  }.scope
+)
+
+(
+  {
+    Mix(
+      Resonz.ar(
+        Saw.ar([440, 443, 437] + SinOsc.ar(100, 0, 100)),
+        XLine.kr(10000, 10, 10),
+        Line.kr(1, 0.05, 10),
+        mul: LFSaw.kr(
+          Line.kr(3, 17, 3), 0, 0.5, 0.5
+        ) * Line.kr(1, 0, 10)
+      )
+    )
+  }.scope
+)
+
+(
+  b = Buffer.read(s, Platform.resourceDir +/+ "sounds/a11wlk01.wav");
+)
+
+(
+  {
+    var modfreq, modindex, modulator;
+
+    modfreq = MouseX.kr(1, 4400, 'exponential');
+    modindex = MouseY.kr(0.0, 10.0, 'linear');
+
+    modulator = SinOsc.kr(modfreq, 0, modfreq * modindex, 440);
+
+    PlayBuf.ar(1, b, BufRateScale.kr(b) * (modulator/440), 1, 0, 1)
+  }.scope;
+)
+
+(
+  var numpartials, spectrum, amplitudes, modfreqs1, modfreqs2, decaytimes;
+
+  spectrum = [0.5, 1, 1.19, 1.56, 2, 2.51, 2.66, 3.01, 4.1];
+
+  amplitudes = [0.25, 1, 0.8, 0.5, 0.9, 0.4, 0.3, 0.6, 0.1];
+
+  numpartials = spectrum.size;
+
+  modfreqs1 = Array.rand(numpartials, 1, 5.0);
+
+  modfreqs2 = Array.rand(numpartials, 0.1, 3.0);
+
+  decaytimes = Array.fill(numpartials, { |i|
+    rrand(2.5, 2.5 + (5 * (1.0 - (1/numpartials))))
+  });
+
+  {
+    Mix.fill(spectrum.size, { arg i;
+      var amp, freq;
+
+      freq = (spectrum[i] + (SinOsc.kr(modfreqs1[i], 0, 0.005))) * 500;
+      amp = 0.1 * Line.kr(1, 0, decaytimes[i]) *
+                  (SinOsc.ar(modfreqs2[i], 0, 0.1, 0.9) * amplitudes[i]);
+
+      Pan2.ar(SinOsc.ar(freq, 0, amp), 1.0.rand2) }
+    )
+  }.scope
+)