diff --git a/src/NoteTrack.cpp b/src/NoteTrack.cpp
index 914a8f6c5..2b78d28da 100644
--- a/src/NoteTrack.cpp
+++ b/src/NoteTrack.cpp
@@ -534,6 +534,18 @@ bool NoteTrack::Paste(double t, const Track *src)
    return true;
 }
 
+bool NoteTrack::Silence(double, double)
+{
+   // to do
+   return false;
+}
+
+bool NoteTrack::InsertSilence(double, double)
+{
+   // to do
+   return false;
+}
+
 // Call this function to manipulate the underlying sequence data. This is
 // NOT the function that handles horizontal dragging.
 bool NoteTrack::Shift(double t) // t is always seconds
diff --git a/src/NoteTrack.h b/src/NoteTrack.h
index a314db574..3a62c50e0 100644
--- a/src/NoteTrack.h
+++ b/src/NoteTrack.h
@@ -105,6 +105,8 @@ class AUDACITY_DLL_API NoteTrack final
    bool Trim (double t0, double t1) /* not override */;
    bool Clear(double t0, double t1) override;
    bool Paste(double t, const Track *src) override;
+   bool Silence(double t0, double t1) override;
+   bool InsertSilence(double t, double len) override;
    bool Shift(double t) /* not override */;
 
 #ifdef EXPERIMENTAL_MIDI_OUT
diff --git a/src/TimeTrack.cpp b/src/TimeTrack.cpp
index 6f47af6f3..a552a1bce 100644
--- a/src/TimeTrack.cpp
+++ b/src/TimeTrack.cpp
@@ -63,20 +63,24 @@ TimeTrack::TimeTrack(const std::shared_ptr<DirManager> &projDirManager, const Zo
    blankPen.SetColour(214, 214, 214);
 }
 
-TimeTrack::TimeTrack(const TimeTrack &orig):
-   Track(orig)
+TimeTrack::TimeTrack(const TimeTrack &orig, double *pT0, double *pT1)
+   : Track(orig)
    , mZoomInfo(orig.mZoomInfo)
 {
    Init(orig);	// this copies the TimeTrack metadata (name, range, etc)
 
    ///@TODO: Give Envelope:: a copy-constructor instead of this?
    mEnvelope = std::make_unique<Envelope>();
+   mEnvelope->Flatten(1.0);
    mEnvelope->SetTrackLen(DBL_MAX);
    SetInterpolateLog(orig.GetInterpolateLog()); // this calls Envelope::SetInterpolateDB
-   mEnvelope->Flatten(1.0);
    mEnvelope->SetOffset(0);
    mEnvelope->SetRange(orig.mEnvelope->GetMinValue(), orig.mEnvelope->GetMaxValue());
-   mEnvelope->Paste(0.0, orig.mEnvelope.get());
+   if ( pT0 && pT1 )
+      // restricted copy
+      mEnvelope->CopyFrom(orig.mEnvelope.get(), *pT0, *pT1);
+   else
+      mEnvelope->Paste(0.0, orig.mEnvelope.get());
 
    ///@TODO: Give Ruler:: a copy-constructor instead of this?
    mRuler = std::make_unique<Ruler>();
@@ -103,6 +107,45 @@ TimeTrack::~TimeTrack()
 {
 }
 
+Track::Holder TimeTrack::Cut( double t0, double t1 )
+{
+   auto result = Copy( t0, t1, false );
+   Clear( t0, t1 );
+   return result;
+}
+
+Track::Holder TimeTrack::Copy( double t0, double t1, bool ) const
+{
+   auto result = std::make_unique<TimeTrack>( *this, &t0, &t1 );
+   return Track::Holder{ std::move( result ) };
+}
+
+bool TimeTrack::Clear(double t0, double t1)
+{
+   mEnvelope->CollapseRegion(t0, t1);
+   return true;
+}
+
+bool TimeTrack::Paste(double t, const Track * src)
+{
+   if (src->GetKind() != Track::Time)
+      return false;
+
+   mEnvelope->Paste(t, static_cast<const TimeTrack*>(src)->mEnvelope.get());
+   return true;
+}
+
+bool TimeTrack::Silence(double t0, double t1)
+{
+   return true;
+}
+
+bool TimeTrack::InsertSilence(double t, double len)
+{
+   mEnvelope->InsertSpace(t, len);
+   return true;
+}
+
 Track::Holder TimeTrack::Duplicate() const
 {
    return std::make_unique<TimeTrack>(*this);
diff --git a/src/TimeTrack.h b/src/TimeTrack.h
index 03aa29860..16e8743c7 100644
--- a/src/TimeTrack.h
+++ b/src/TimeTrack.h
@@ -34,11 +34,20 @@ class TimeTrack final : public Track {
     * Envelope:: and Ruler:: members in order to copy one to the other - unfortunately both lack a
     * copy-constructor to encapsulate this.
     * @param orig The original track to copy from
+    * @param pT0 if not null, then the start of the sub-range to copy
+    * @param pT1 if not null, then the end of the sub-range to copy
     */
-   TimeTrack(const TimeTrack &orig);
+   TimeTrack(const TimeTrack &orig, double *pT0 = nullptr, double *pT1 = nullptr);
 
    virtual ~TimeTrack();
 
+   Holder Cut( double t0, double t1 ) override;
+   Holder Copy( double t0, double t1, bool forClipboard ) const override;
+   bool Clear(double t0, double t1) override;
+   bool Paste(double t, const Track * src) override;
+   bool Silence(double t0, double t1) override;
+   bool InsertSilence(double t, double len) override;
+
    // Identifying the type of track
    int GetKind() const override { return Time; }
 
diff --git a/src/Track.h b/src/Track.h
index 2b74e076d..334efeb41 100644
--- a/src/Track.h
+++ b/src/Track.h
@@ -206,28 +206,29 @@ class AUDACITY_DLL_API Track /* not final */ : public XMLTagHandler
    // separate from the Track.
    const std::shared_ptr<DirManager> &GetDirManager() const { return mDirManager; }
 
-   // Create a NEW track and modify this track (or return null for failure)
-   virtual Holder Cut(double WXUNUSED(t0), double WXUNUSED(t1)) { return{}; }
+   // Create a NEW track and modify this track
+   // Return non-NULL or else throw
+   virtual Holder Cut(double WXUNUSED(t0), double WXUNUSED(t1)) = 0;
 
-   // Create a NEW track and don't modify this track (or return null for failure)
+   // Create a NEW track and don't modify this track
+   // Return non-NULL or else throw
    // Note that subclasses may want to distinguish tracks stored in a clipboard
    // from those stored in a project
    virtual Holder Copy
-      (double WXUNUSED(t0), double WXUNUSED(t1), bool forClipboard = true) const
-   { return{}; }
+      (double WXUNUSED(t0), double WXUNUSED(t1), bool forClipboard = true) const = 0;
 
    // Return true for success
-   virtual bool Clear(double WXUNUSED(t0), double WXUNUSED(t1)) {return false;}
+   virtual bool Clear(double WXUNUSED(t0), double WXUNUSED(t1)) = 0;
 
    // Return true for success
-   virtual bool Paste(double WXUNUSED(t), const Track * WXUNUSED(src)) {return false;}
+   virtual bool Paste(double WXUNUSED(t), const Track * WXUNUSED(src)) = 0;
 
    // This can be used to adjust a sync-lock selected track when the selection
    // is replaced by one of a different length.
    virtual bool SyncLockAdjust(double oldT1, double newT1);
 
-   virtual bool Silence(double WXUNUSED(t0), double WXUNUSED(t1)) {return false;}
-   virtual bool InsertSilence(double WXUNUSED(t), double WXUNUSED(len)) {return false;}
+   virtual bool Silence(double WXUNUSED(t0), double WXUNUSED(t1)) = 0;
+   virtual bool InsertSilence(double WXUNUSED(t), double WXUNUSED(len)) = 0;
 
    virtual int GetKind() const { return None; }