diff --git a/sclang-play/noisy.sc b/sclang-play/noisy.sc
new file mode 100644
index 0000000..26cfefd
--- /dev/null
+++ b/sclang-play/noisy.sc
@@ -0,0 +1,15 @@
+(
+  s.boot;
+)
+
+(
+  {
+    var freqCutoff = MouseX.kr(400, 2000);
+    var ampl = MouseY.kr(0.1, 1.5);
+    var out = LPF.ar(
+      WhiteNoise.ar(mul: ampl),
+      freq: freqCutoff
+    );
+    [out, out]
+  }.scope
+)
diff --git a/sclang-play/tut/ch02.sc b/sclang-play/tut/ch02.sc
index 015ce1e..475175f 100644
--- a/sclang-play/tut/ch02.sc
+++ b/sclang-play/tut/ch02.sc
@@ -193,3 +193,128 @@
     Mix(SinOsc.ar(250 * (1..n), 0, 1/n))
   }.scope
 )
+
+// 2.2
+
+(
+  {
+    SinOsc.ar(mul: 0.1)
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(mul: 2.0)
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(mul: 0.1)
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(
+      mul: MouseY.kr(1.0, 0.1)
+    )
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(
+      mul: 0.1, add: MouseY.kr(0.9, -0.9)
+    )
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(
+      mul: MouseX.kr(0.1, 1.0),
+      add: MouseY.kr(0.9, -0.9)
+    )
+  }.scope
+)
+
+(
+  {
+    var cutoff = SinOsc.ar(
+      1,
+      mul: MouseX.kr(0.0, 1700.0),
+      add: 2000.0
+    );
+
+    LPF.ar(
+      WhiteNoise.ar,
+      freq: cutoff
+    );
+  }.scope
+)
+
+(
+  {
+    0.1 * SinOsc.ar
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(mul: 0.1)
+  }.scope
+)
+
+(
+  {
+    0.1 * SinOsc.ar + 0.5
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(mul: 0.1, add: 0.5)
+  }.scope
+)
+
+(
+  {
+    var cutoff = SinOsc.ar(1) * 1700.0 + 2000.0;
+    LPF.ar(WhiteNoise.ar, freq: cutoff)
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(440, 0.0, 0.1, 0.0)
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(MouseX.kr(440, 880), 0.0, 0.1, 0.0)
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(MouseX.kr(440, 880), mul: 0.1)
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(440, mul: -20.dbamp)
+  }.scope
+)
+
+(
+  {
+    SinOsc.ar(
+      40 * SinOsc.ar(MouseX.kr(1, 20)) + 440,
+      0,
+      0.1
+    )
+  }.scope
+)