diff --git a/src/effects/ChangePitch.cpp b/src/effects/ChangePitch.cpp
index a375b1a3e..e5bb1515e 100644
--- a/src/effects/ChangePitch.cpp
+++ b/src/effects/ChangePitch.cpp
@@ -221,7 +221,7 @@ bool EffectChangePitch::Process()
       proxy.mProxyEffectName = XO("High Quality Pitch Change");
       proxy.setParameters(1.0, pitchRatio);
 
-      return Delegate( proxy );
+      return Delegate(proxy, *mUIParent, nullptr);
    }
    else
 #endif
diff --git a/src/effects/ChangeTempo.cpp b/src/effects/ChangeTempo.cpp
index f8133cdf3..bf66e30ab 100644
--- a/src/effects/ChangeTempo.cpp
+++ b/src/effects/ChangeTempo.cpp
@@ -207,7 +207,7 @@ bool EffectChangeTempo::Process()
       EffectSBSMS proxy;
       proxy.mProxyEffectName = XO("High Quality Tempo Change");
       proxy.setParameters(tempoRatio, 1.0);
-      success = Delegate( proxy );
+      success = Delegate(proxy, *mUIParent, nullptr);
    }
    else
 #endif
diff --git a/src/effects/Effect.cpp b/src/effects/Effect.cpp
index c24270a11..ae0766e3d 100644
--- a/src/effects/Effect.cpp
+++ b/src/effects/Effect.cpp
@@ -1320,13 +1320,14 @@ bool Effect::DoEffect(double projectRate,
    return returnVal;
 }
 
-bool Effect::Delegate( Effect &delegate )
+bool Effect::Delegate(
+   Effect &delegate, wxWindow &parent, const EffectDialogFactory &factory )
 {
    NotifyingSelectedRegion region;
    region.setTimes( mT0, mT1 );
 
-   return delegate.DoEffect(
-      mProjectRate, mTracks, mFactory, region );
+   return delegate.DoEffect( mProjectRate, mTracks, mFactory,
+      region, &parent, factory );
 }
 
 // All legacy effects should have this overridden
diff --git a/src/effects/Effect.h b/src/effects/Effect.h
index f3cf8827d..93cff76f3 100644
--- a/src/effects/Effect.h
+++ b/src/effects/Effect.h
@@ -262,7 +262,8 @@ class AUDACITY_DLL_API Effect /* not final */ : public wxEvtHandler,
       wxWindow *pParent = nullptr,
       const EffectDialogFactory &dialogFactory = {} );
 
-   bool Delegate( Effect &delegate );
+   bool Delegate( Effect &delegate,
+      wxWindow &parent, const EffectDialogFactory &factory );
 
    virtual bool IsHidden();
 
diff --git a/src/effects/nyquist/Nyquist.cpp b/src/effects/nyquist/Nyquist.cpp
index e9ded20e2..9d7bc54fd 100644
--- a/src/effects/nyquist/Nyquist.cpp
+++ b/src/effects/nyquist/Nyquist.cpp
@@ -544,8 +544,6 @@ bool NyquistEffect::SetAutomationParameters(CommandParameters & parms)
 
 bool NyquistEffect::Init()
 {
-   mDelegate.reset();
-
    // When Nyquist Prompt spawns an effect GUI, Init() is called for Nyquist Prompt,
    // and then again for the spawned (mExternal) effect.
 
@@ -620,21 +618,17 @@ bool NyquistEffect::Init()
    return true;
 }
 
+bool NyquistEffect::CheckWhetherSkipEffect()
+{
+   // If we're a prompt and we have controls, then we've already processed
+   // the audio, so skip further processing.
+   return (mIsPrompt && mControls.size() > 0);
+}
+
 static void RegisterFunctions();
 
 bool NyquistEffect::Process()
 {
-   if (mDelegate)
-   {
-      mProgress->Hide();
-      auto &effect = *mDelegate;
-      auto result = Delegate( effect );
-      mT0 = effect.mT0;
-      mT1 = effect.mT1;
-      mDelegate.reset();
-      return result;
-   }
-
    // Check for reentrant Nyquist commands.
    // I'm choosing to mark skipped Nyquist commands as successful even though
    // they are skipped.  The reason is that when Nyquist calls out to a chain,
@@ -654,6 +648,10 @@ bool NyquistEffect::Process()
    EffectManager & em = EffectManager::Get();
    em.SetSkipStateFlag(false);
 
+   if (mExternal) {
+      mProgress->Hide();
+   }
+
    mOutputTime = 0;
    mCount = 0;
    mProgressIn = 0;
@@ -1016,14 +1014,14 @@ bool NyquistEffect::ShowInterface(
       return res;
    }
 
-   // Come here only in case the user entered a script into the Nyquist
-   // prompt window that included the magic comments that specify controls.
-   // Interpret those comments and put up a second dialog.
-   mDelegate = std::make_unique< NyquistEffect >( NYQUIST_WORKER_ID );
-   auto &effect = *mDelegate;
+   NyquistEffect effect(NYQUIST_WORKER_ID);
+
    effect.SetCommand(mInputCmd);
    effect.mDebug = (mUIResultID == eDebugID);
-   return effect.ShowInterface( parent, factory, forceModal );
+   bool result = Delegate(effect, parent, factory);
+   mT0 = effect.mT0;
+   mT1 = effect.mT1;
+   return result;
 }
 
 void NyquistEffect::PopulateOrExchange(ShuttleGui & S)
diff --git a/src/effects/nyquist/Nyquist.h b/src/effects/nyquist/Nyquist.h
index 5143a1b8e..b1ac01af4 100644
--- a/src/effects/nyquist/Nyquist.h
+++ b/src/effects/nyquist/Nyquist.h
@@ -97,6 +97,7 @@ public:
    // Effect implementation
 
    bool Init() override;
+   bool CheckWhetherSkipEffect() override;
    bool Process() override;
    bool ShowInterface( wxWindow &parent,
       const EffectDialogFactory &factory, bool forceModal = false) override;
@@ -188,8 +189,6 @@ private:
 
 private:
 
-   std::unique_ptr<NyquistEffect> mDelegate;
-
    wxString          mXlispPath;
 
    wxFileName        mFileName;  ///< Name of the Nyquist script file this effect is loaded from