diff --git a/CMakeLists.txt b/CMakeLists.txt
index 25d67568..00aee295 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,46 +16,47 @@ add_subdirectory(common)
 add_subdirectory(lib/vst3sdk)
 smtg_enable_vst3_sdk()
 
-add_subdirectory(AccumulativeRingMod)
-add_subdirectory(BasicLimiter)
-add_subdirectory(BasicLimiterAutoMake)
-add_subdirectory(ClangCymbal)
-add_subdirectory(ClangSynth)
-add_subdirectory(CollidingCombSynth)
-add_subdirectory(CombDistortion)
-add_subdirectory(CubicPadSynth)
-add_subdirectory(EnvelopedSine)
-add_subdirectory(EsPhaser)
-add_subdirectory(FDN64Reverb)
-add_subdirectory(FDNCymbal)
-add_subdirectory(FeedbackPhaser)
-add_subdirectory(FoldShaper)
+# add_subdirectory(AccumulativeRingMod)
+# add_subdirectory(BasicLimiter)
+# add_subdirectory(BasicLimiterAutoMake)
+# add_subdirectory(ClangCymbal)
+# add_subdirectory(ClangSynth)
+# add_subdirectory(CollidingCombSynth)
+# add_subdirectory(CombDistortion)
+# add_subdirectory(CubicPadSynth)
+# add_subdirectory(EnvelopedSine)
+# add_subdirectory(EsPhaser)
+# add_subdirectory(FDN64Reverb)
+# add_subdirectory(FDNCymbal)
+# add_subdirectory(FeedbackPhaser)
+# add_subdirectory(FoldShaper)
 add_subdirectory(GenericDrum)
-add_subdirectory(IterativeSinCluster)
-add_subdirectory(L3Reverb)
-add_subdirectory(L4Reverb)
-add_subdirectory(LatticeReverb)
-add_subdirectory(LightPadSynth)
-add_subdirectory(LongPhaser)
-add_subdirectory(MatrixShifter)
-add_subdirectory(MaybeSnare)
-add_subdirectory(MembraneSynth)
-add_subdirectory(MiniCliffEQ)
-add_subdirectory(ModuloShaper)
-add_subdirectory(NarrowingDelay)
-add_subdirectory(OddPowShaper)
-add_subdirectory(OrdinaryPhaser)
-add_subdirectory(ParallelComb)
-add_subdirectory(ParallelDetune)
-add_subdirectory(PitchShiftDelay)
-add_subdirectory(RingModSpacer)
-add_subdirectory(SevenDelay)
-add_subdirectory(SoftClipper)
-add_subdirectory(SyncSawSynth)
-add_subdirectory(TrapezoidSynth)
-add_subdirectory(UltraSynth)
-add_subdirectory(UltrasonicRingMod)
-add_subdirectory(WaveCymbal)
+
+# add_subdirectory(IterativeSinCluster)
+# add_subdirectory(L3Reverb)
+# add_subdirectory(L4Reverb)
+# add_subdirectory(LatticeReverb)
+# add_subdirectory(LightPadSynth)
+# add_subdirectory(LongPhaser)
+# add_subdirectory(MatrixShifter)
+# add_subdirectory(MaybeSnare)
+# add_subdirectory(MembraneSynth)
+# add_subdirectory(MiniCliffEQ)
+# add_subdirectory(ModuloShaper)
+# add_subdirectory(NarrowingDelay)
+# add_subdirectory(OddPowShaper)
+# add_subdirectory(OrdinaryPhaser)
+# add_subdirectory(ParallelComb)
+# add_subdirectory(ParallelDetune)
+# add_subdirectory(PitchShiftDelay)
+# add_subdirectory(RingModSpacer)
+# add_subdirectory(SevenDelay)
+# add_subdirectory(SoftClipper)
+# add_subdirectory(SyncSawSynth)
+# add_subdirectory(TrapezoidSynth)
+# add_subdirectory(UltraSynth)
+# add_subdirectory(UltrasonicRingMod)
+# add_subdirectory(WaveCymbal)
 
 # ## Below are prototype plugins. Breaking changes will be introduced.
 # add_subdirectory(TestBedSynth)
diff --git a/GenericDrum/source/editor.cpp b/GenericDrum/source/editor.cpp
index 289e0494..c4fd9a24 100644
--- a/GenericDrum/source/editor.cpp
+++ b/GenericDrum/source/editor.cpp
@@ -17,6 +17,7 @@
 
 #include "editor.hpp"
 #include "../../lib/pcg-cpp/pcg_random.hpp"
+#include "gui/randomizebutton.hpp"
 #include "version.hpp"
 
 #include <algorithm>
@@ -36,7 +37,7 @@ constexpr float labelY = labelHeight + 2 * margin;
 constexpr float labelWidth = 2 * knobWidth;
 constexpr float groupLabelWidth = 2 * labelWidth + 2 * margin;
 constexpr float splashWidth = int(labelWidth * 3 / 2) + 2 * margin;
-constexpr float splashHeight = int(labelHeight * 3 / 2);
+constexpr float splashHeight = int(2 * labelHeight + 2 * margin);
 
 constexpr float barBoxWidth = groupLabelWidth;
 constexpr float barBoxHeight = 5 * labelY - 2 * margin;
@@ -523,12 +524,22 @@ bool Editor::prepareUI()
     secondaryLeft0, secondaryTop5, groupLabelWidth, labelHeight, uiTextSize,
     "Membrane collision status.");
 
+  // Randomize button.
+  const auto randomButtonTop = top0 + 18 * labelY;
+  const auto randomButtonLeft = left0 + labelWidth + 2 * margin;
+  auto panicButton = new RandomizeButton(
+    CRect(
+      randomButtonLeft, randomButtonTop, randomButtonLeft + labelWidth,
+      randomButtonTop + splashHeight),
+    this, 0, "Random", getFont(pluginNameTextSize), palette, this);
+  frame->addView(panicButton);
+
   // Plugin name.
   constexpr auto splashMargin = uiMargin;
-  constexpr auto splashTop = top0 + 18 * labelY + int(labelHeight / 4) + 2 * margin;
-  constexpr auto splashLeft = left0 + int(labelWidth / 4);
+  constexpr auto splashTop = top0 + 18 * labelY;
+  constexpr auto splashLeft = left0;
   addSplashScreen(
-    splashLeft, splashTop, splashWidth, splashHeight, splashMargin, splashMargin,
+    splashLeft, splashTop, labelWidth, splashHeight, splashMargin, splashMargin,
     defaultWidth - 2 * splashMargin, defaultHeight - 2 * splashMargin, pluginNameTextSize,
     "GenericDrum", false);
 
diff --git a/GenericDrum/source/gui/randomizebutton.hpp b/GenericDrum/source/gui/randomizebutton.hpp
new file mode 100644
index 00000000..2759c11e
--- /dev/null
+++ b/GenericDrum/source/gui/randomizebutton.hpp
@@ -0,0 +1,207 @@
+// (c) 2023 Takamitsu Endo
+//
+// This file is part of GenericDrum.
+//
+// GenericDrum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GenericDrum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GenericDrum.  If not, see <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include "public.sdk/source/vst/vsteditcontroller.h"
+#include "vstgui/vstgui.h"
+
+#include "../../../common/gui/plugeditor.hpp"
+#include "../../../common/gui/style.hpp"
+#include "../parameter.hpp"
+
+#include <algorithm>
+#include <random>
+#include <string>
+
+namespace VSTGUI {
+
+class RandomizeButton : public CControl {
+public:
+  std::string label;
+
+  RandomizeButton(
+    const CRect &size,
+    IControlListener *listener,
+    int32_t tag,
+    std::string label,
+    const SharedPointer<CFontDesc> &fontId,
+    Uhhyou::Palette &palette,
+    Steinberg::Vst::PlugEditor *editor)
+    : CControl(size, listener, tag)
+    , label(label)
+    , fontId(fontId)
+    , pal(palette)
+    , editor(editor)
+  {
+    if (editor) editor->remember();
+  }
+
+  ~RandomizeButton()
+  {
+    if (editor) editor->forget();
+  }
+
+  void draw(CDrawContext *pContext) override
+  {
+    pContext->setDrawMode(CDrawMode(CDrawModeFlags::kAntiAliasing));
+    CDrawContext::Transform t(
+      *pContext, CGraphicsTransform().translate(getViewSize().getTopLeft()));
+
+    // Border.
+    const double borderW = isMouseEntered ? 2 * borderWidth : borderWidth;
+    const double halfBorderWidth = int(borderW / 2.0);
+    pContext->setFillColor(isPressed ? pal.highlightButton() : pal.boxBackground());
+    pContext->setFrameColor(
+      isMouseEntered && !isPressed ? pal.highlightButton() : pal.border());
+    pContext->setLineWidth(borderW);
+    pContext->drawRect(
+      CRect(
+        halfBorderWidth, halfBorderWidth, getWidth() - halfBorderWidth,
+        getHeight() - halfBorderWidth),
+      kDrawFilledAndStroked);
+
+    // Text
+    pContext->setFont(fontId);
+    pContext->setFontColor(pal.foreground());
+    pContext->drawString(
+      label.c_str(), CRect(0, 0, getWidth(), getHeight()), kCenterText);
+  }
+
+  void onMouseEnterEvent(MouseEnterEvent &event) override
+  {
+    isMouseEntered = true;
+    invalid();
+    event.consumed = true;
+  }
+
+  void onMouseExitEvent(MouseExitEvent &event) override
+  {
+    if (value == 1.0f) {
+      value = 0.0f;
+    }
+    isPressed = false;
+    isMouseEntered = false;
+    invalid();
+    event.consumed = true;
+  }
+
+  void onMouseDownEvent(MouseDownEvent &event) override
+  {
+    using ID = Steinberg::Synth::ParameterID::ID;
+
+    if (!event.buttonState.isLeft()) return;
+    isPressed = true;
+    value = 1.0f;
+
+    if (editor) {
+      using Rng = std::mt19937_64;
+
+      std::random_device source;
+      std::random_device::result_type
+        random_data[(Rng::state_size - 1) / sizeof(source()) + 1];
+      std::generate(std::begin(random_data), std::end(random_data), std::ref(source));
+      std::seed_seq seeds(std::begin(random_data), std::end(random_data));
+      Rng rng(seeds);
+
+      std::uniform_real_distribution<Steinberg::Vst::ParamValue> uniform{0.0, 1.0};
+      setParam(ID::seed, uniform(rng));
+      setParam(ID::noiseDecaySeconds, uniform(rng));
+      setParam(ID::noiseLowpassHz, uniform(rng));
+      setParam(ID::noiseAllpassMaxTimeHz, uniform(rng));
+
+      setParam(ID::impactWireMix, uniform(rng));
+      setParam(ID::membraneWireMix, uniform(rng));
+      setParam(ID::wireFrequencyHz, uniform(rng));
+      setParam(ID::wireDecaySeconds, uniform(rng));
+      setParam(ID::wireDistance, uniform(rng));
+      setParam(ID::wireCollisionTypeMix, uniform(rng));
+
+      // setParam(ID::crossFeedbackGain, uniform(rng));
+      for (int idx = 0; idx < maxFdnSize; ++idx) {
+        setParam(ID::crossFeedbackRatio0 + idx, uniform(rng));
+      }
+
+      setParam(ID::delayTimeSpread, uniform(rng));
+      setParam(ID::bandpassCutSpread, uniform(rng));
+      setParam(ID::pitchRandomCent, uniform(rng));
+
+      setParam(ID::envelopeAttackSeconds, uniform(rng));
+      setParam(ID::envelopeDecaySeconds, uniform(rng));
+      setParam(ID::envelopeModAmount, uniform(rng));
+
+      // setParam(ID::pitchType, uniform(rng));
+      setParam(ID::delayTimeHz, uniform(rng));
+      setParam(ID::delayTimeModAmount, uniform(rng));
+      setParam(ID::bandpassCutRatio, uniform(rng));
+      setParam(ID::bandpassQ, uniform(rng));
+
+      setParam(ID::secondaryFdnMix, uniform(rng));
+      setParam(ID::secondaryPitchOffset, uniform(rng));
+      setParam(ID::secondaryQOffset, uniform(rng));
+      setParam(ID::secondaryDistance, uniform(rng));
+    }
+
+    invalid();
+    event.consumed = true;
+  }
+
+  void onMouseUpEvent(MouseUpEvent &event) override
+  {
+    if (isPressed) {
+      isPressed = false;
+      value = 0.0f;
+      invalid();
+    }
+    event.consumed = true;
+  }
+
+  void onMouseCancelEvent(MouseCancelEvent &event) override
+  {
+    if (isPressed) {
+      isPressed = false;
+      value = 0;
+      invalid();
+    }
+    isMouseEntered = false;
+    event.consumed = true;
+  }
+
+  void setBorderWidth(CCoord width) { borderWidth = width < 0 ? 0 : width; }
+
+  CLASS_METHODS(RandomizeButton, CControl);
+
+private:
+  // Before calling check if `editor` is not nullptr.
+  inline void setParam(Steinberg::Vst::ParamID id, Steinberg::Vst::ParamValue value)
+  {
+    editor->valueChanged(id, value);
+    editor->updateUI(id, value);
+  }
+
+  Steinberg::Vst::PlugEditor *editor = nullptr;
+
+  SharedPointer<CFontDesc> fontId;
+  Uhhyou::Palette &pal;
+
+  CCoord borderWidth = 1.0;
+
+  bool isPressed = false;
+  bool isMouseEntered = false;
+};
+
+} // namespace VSTGUI
diff --git a/GenericDrum/source/version.hpp b/GenericDrum/source/version.hpp
index 9ebc7225..f8665d63 100644
--- a/GenericDrum/source/version.hpp
+++ b/GenericDrum/source/version.hpp
@@ -29,11 +29,11 @@
 #define SUB_VERSION_STR "1"
 #define SUB_VERSION_INT 1
 
-#define RELEASE_NUMBER_STR "0"
-#define RELEASE_NUMBER_INT 0
+#define RELEASE_NUMBER_STR "1"
+#define RELEASE_NUMBER_INT 1
 
-#define BUILD_NUMBER_STR "5"
-#define BUILD_NUMBER_INT 5
+#define BUILD_NUMBER_STR "6"
+#define BUILD_NUMBER_INT 6
 
 #define FULL_VERSION_STR                                                                 \
   MAJOR_VERSION_STR "." SUB_VERSION_STR "." RELEASE_NUMBER_STR "." BUILD_NUMBER_STR