diff --git a/src/AudioIOListener.h b/src/AudioIOListener.h
index 054e6ff65..29f110143 100644
--- a/src/AudioIOListener.h
+++ b/src/AudioIOListener.h
@@ -15,8 +15,6 @@
 
 #include "Audacity.h"
 
-class AutoSaveFile;
-
 class AUDACITY_DLL_API AudioIOListener /* not final */ {
 public:
    AudioIOListener() {}
diff --git a/src/AutoRecovery.cpp b/src/AutoRecovery.cpp
index a4ac5ade9..5a55f6ee0 100644
--- a/src/AutoRecovery.cpp
+++ b/src/AutoRecovery.cpp
@@ -219,22 +219,6 @@ void AutoSaveFile::WriteSubTree(const AutoSaveFile & value)
    mBuffer.AppendByte(FT_Pop);
 }
 
-bool AutoSaveFile::Write(wxFFile & file) const
-{
-   return Append(file);
-}
-
-bool AutoSaveFile::Append(wxFFile & file) const
-{
-   bool success = file.Write(mDict.GetData(), mDict.GetDataLen()) == mDict.GetDataLen();
-   if (success)
-   {
-      success = file.Write(mBuffer.GetData(), mBuffer.GetDataLen()) == mBuffer.GetDataLen();
-   }
-
-   return success;
-}
-
 void AutoSaveFile::WriteName(const wxString & name)
 {
    wxASSERT(name.length() * sizeof(wxChar) <= SHRT_MAX);
diff --git a/src/AutoRecovery.h b/src/AutoRecovery.h
index 139918e05..03023d12d 100644
--- a/src/AutoRecovery.h
+++ b/src/AutoRecovery.h
@@ -55,9 +55,6 @@ public:
    // Non-override functions
    void WriteSubTree(const AutoSaveFile & value);
 
-   bool Write(wxFFile & file) const;
-   bool Append(wxFFile & file) const;
-
    const wxMemoryBuffer &GetDict() const;
    const wxMemoryBuffer &GetData() const;
 
diff --git a/src/LabelTrack.cpp b/src/LabelTrack.cpp
index 4db0675c1..267383e22 100644
--- a/src/LabelTrack.cpp
+++ b/src/LabelTrack.cpp
@@ -68,11 +68,11 @@ static ProjectFileIORegistry::Entry registerFactory{
 
 LabelTrack::Holder TrackFactory::NewLabelTrack()
 {
-   return std::make_shared<LabelTrack>(&mProject);
+   return std::make_shared<LabelTrack>();
 }
 
-LabelTrack::LabelTrack(AudacityProject *project):
-   Track(project),
+LabelTrack::LabelTrack():
+   Track(),
    mClipLen(0.0),
    miLastLabel(-1)
 {
@@ -652,7 +652,7 @@ Track::Holder LabelTrack::SplitCut(double t0, double t1)
 
 Track::Holder LabelTrack::Copy(double t0, double t1, bool) const
 {
-   auto tmp = std::make_shared<LabelTrack>(GetProject());
+   auto tmp = std::make_shared<LabelTrack>();
    const auto lt = static_cast<LabelTrack*>(tmp.get());
 
    for (auto &labelStruct: mLabels) {
diff --git a/src/LabelTrack.h b/src/LabelTrack.h
index 48fd3792c..98f334f02 100644
--- a/src/LabelTrack.h
+++ b/src/LabelTrack.h
@@ -87,7 +87,7 @@ class AUDACITY_DLL_API LabelTrack final
    , public wxEvtHandler
 {
  public:
-   LabelTrack(AudacityProject *project);
+   LabelTrack();
    LabelTrack(const LabelTrack &orig);
 
    virtual ~ LabelTrack();
diff --git a/src/NoteTrack.cpp b/src/NoteTrack.cpp
index faec011a1..f9389b831 100644
--- a/src/NoteTrack.cpp
+++ b/src/NoteTrack.cpp
@@ -123,11 +123,11 @@ static ProjectFileIORegistry::Entry registerFactory{
 
 NoteTrack::Holder TrackFactory::NewNoteTrack()
 {
-   return std::make_shared<NoteTrack>(&mProject);
+   return std::make_shared<NoteTrack>();
 }
 
-NoteTrack::NoteTrack(AudacityProject *project)
-   : NoteTrackBase(project)
+NoteTrack::NoteTrack()
+   : NoteTrackBase()
 {
    SetDefaultName(_("Note Track"));
    SetName(GetDefaultName());
@@ -172,7 +172,7 @@ Alg_seq &NoteTrack::GetSeq() const
 
 Track::Holder NoteTrack::Clone() const
 {
-   auto duplicate = std::make_shared<NoteTrack>(mProject);
+   auto duplicate = std::make_shared<NoteTrack>();
    duplicate->Init(*this);
    // The duplicate begins life in serialized state.  Often the duplicate is
    // pushed on the Undo stack.  Then we want to un-serialize it (or a further
@@ -463,7 +463,7 @@ Track::Holder NoteTrack::Cut(double t0, double t1)
       //( std::min( t1, GetEndTime() ) ) - ( std::max( t0, GetStartTime() ) )
    //);
 
-   auto newTrack = std::make_shared<NoteTrack>(mProject);
+   auto newTrack = std::make_shared<NoteTrack>();
 
    newTrack->Init(*this);
 
@@ -477,7 +477,7 @@ Track::Holder NoteTrack::Cut(double t0, double t1)
    //AddToDuration( delta );
 
    // What should be done with the rest of newTrack's members?
-   //(mBottomNote, mProject,
+   //(mBottomNote,
    // mSerializationBuffer, mSerializationLength, mVisibleChannels)
 
    return newTrack;
@@ -490,7 +490,7 @@ Track::Holder NoteTrack::Copy(double t0, double t1, bool) const
 
    double len = t1-t0;
 
-   auto newTrack = std::make_shared<NoteTrack>(mProject);
+   auto newTrack = std::make_shared<NoteTrack>();
 
    newTrack->Init(*this);
 
@@ -500,7 +500,7 @@ Track::Holder NoteTrack::Copy(double t0, double t1, bool) const
    newTrack->SetOffset(0);
 
    // What should be done with the rest of newTrack's members?
-   // (mBottomNote, mProject, mSerializationBuffer,
+   // (mBottomNote, mSerializationBuffer,
    // mSerializationLength, mVisibleChannels)
 
    return newTrack;
diff --git a/src/NoteTrack.h b/src/NoteTrack.h
index 716d17eb6..91295ce81 100644
--- a/src/NoteTrack.h
+++ b/src/NoteTrack.h
@@ -65,7 +65,7 @@ class AUDACITY_DLL_API NoteTrack final
    : public NoteTrackBase
 {
 public:
-   NoteTrack(AudacityProject *project);
+   NoteTrack();
    virtual ~NoteTrack();
 
    using Holder = std::shared_ptr<NoteTrack>;
diff --git a/src/ProjectFileIO.cpp b/src/ProjectFileIO.cpp
index 59cac034c..878b71a1d 100644
--- a/src/ProjectFileIO.cpp
+++ b/src/ProjectFileIO.cpp
@@ -1245,7 +1245,7 @@ const TranslatableString & ProjectFileIO::GetLastError() const
 
 const TranslatableString & ProjectFileIO::GetLibraryError() const
 {
-   return mLastError;
+   return mLibraryError;
 }
 
 void ProjectFileIO::SetError(const TranslatableString & msg)
diff --git a/src/ProjectFileIO.h b/src/ProjectFileIO.h
index 61b17bb23..d6bfab924 100644
--- a/src/ProjectFileIO.h
+++ b/src/ProjectFileIO.h
@@ -80,7 +80,6 @@ private:
    void UpdatePrefs() override;
 
    using ExecCB = std::function<int(wxString *result, int cols, char **vals, char **names)>;
-   using ExecFunc = int (*)(void *data, int cols, char **vals, char **names);
    struct ExecParm
    {
       ExecCB func;
diff --git a/src/SampleBlock.cpp b/src/SampleBlock.cpp
index 99c08f70a..a0bb66bb2 100644
--- a/src/SampleBlock.cpp
+++ b/src/SampleBlock.cpp
@@ -144,8 +144,7 @@ SampleBlockPtr SampleBlock::Get(AudacityProject *project,
 }
 
 SampleBlock::SampleBlock(AudacityProject *project)
-:  mProject(project),
-   mIO(ProjectFileIO::Get(*project))
+:  mIO(ProjectFileIO::Get(*project))
 {
    mValid = false;
    mSilent = false;
diff --git a/src/SampleBlock.h b/src/SampleBlock.h
index 61798feeb..cdcac4b3e 100644
--- a/src/SampleBlock.h
+++ b/src/SampleBlock.h
@@ -103,7 +103,6 @@ private:
    void CalcSummary();
 
 private:
-   AudacityProject *mProject;
    ProjectFileIO & mIO;
    bool mValid;
    bool mDirty;
@@ -128,7 +127,6 @@ private:
    const char *columns =
       "sampleformat, summin, summax, sumrms, summary256, summary64k, samples";
 
-   friend class ProjectFileIO;
 #if defined(WORDS_BIGENDIAN)
 #error All sample block data is little endian...big endian not yet supported
 #endif
diff --git a/src/Sequence.cpp b/src/Sequence.cpp
index e1c121cac..a7d265c02 100644
--- a/src/Sequence.cpp
+++ b/src/Sequence.cpp
@@ -40,7 +40,6 @@
 #include <wx/ffile.h>
 #include <wx/log.h>
 
-#include "ProjectFileIO.h"
 #include "SampleBlock.h"
 #include "InconsistencyException.h"
 #include "widgets/AudacityMessageBox.h"
diff --git a/src/TimeTrack.cpp b/src/TimeTrack.cpp
index fcd15ffab..b26136e9d 100644
--- a/src/TimeTrack.cpp
+++ b/src/TimeTrack.cpp
@@ -38,7 +38,7 @@
 
 std::shared_ptr<TimeTrack> TrackFactory::NewTimeTrack()
 {
-   return std::make_shared<TimeTrack>(&mProject, mZoomInfo);
+   return std::make_shared<TimeTrack>(mZoomInfo);
 }
 
 static ProjectFileIORegistry::Entry registerFactory{
@@ -53,8 +53,8 @@ static ProjectFileIORegistry::Entry registerFactory{
    }
 };
 
-TimeTrack::TimeTrack(AudacityProject *project, const ZoomInfo *zoomInfo):
-   Track(project)
+TimeTrack::TimeTrack(const ZoomInfo *zoomInfo):
+   Track()
    , mZoomInfo(zoomInfo)
 {
    mEnvelope = std::make_unique<BoundedEnvelope>(true, TIMETRACK_MIN, TIMETRACK_MAX, 1.0);
diff --git a/src/TimeTrack.h b/src/TimeTrack.h
index 6807e8f02..6fad911dd 100644
--- a/src/TimeTrack.h
+++ b/src/TimeTrack.h
@@ -25,7 +25,7 @@ class TimeTrack final : public Track {
 
  public:
 
-   TimeTrack(AudacityProject *project, const ZoomInfo *zoomInfo);
+   TimeTrack(const ZoomInfo *zoomInfo);
    /** @brief Copy-Constructor - create a NEW TimeTrack:: which is an independent copy of the original
     *
     * Calls TimeTrack::Init() to copy the track metadata, then does a bunch of manipulations on the
diff --git a/src/Track.cpp b/src/Track.cpp
index df95f3031..87bb583d2 100644
--- a/src/Track.cpp
+++ b/src/Track.cpp
@@ -46,9 +46,8 @@ and TimeTrack.
 #pragma warning( disable : 4786 )
 #endif
 
-Track::Track(AudacityProject *project)
-:  vrulerSize(36,0),
-   mProject(project)
+Track::Track()
+:  vrulerSize(36,0)
 {
    mSelected  = false;
    mLinked    = false;
@@ -76,8 +75,6 @@ void Track::Init(const Track &orig)
    mDefaultName = orig.mDefaultName;
    mName = orig.mName;
 
-   mProject = orig.mProject;
-
    mSelected = orig.mSelected;
    mLinked = orig.mLinked;
    mChannel = orig.mChannel;
diff --git a/src/Track.h b/src/Track.h
index 77d739d21..eab35bd5a 100644
--- a/src/Track.h
+++ b/src/Track.h
@@ -309,11 +309,9 @@ private:
    ChannelType         mChannel;
    double              mOffset;
 
-   mutable AudacityProject *mProject;
-
  public:
 
-   Track(AudacityProject *project);
+   Track();
    Track(const Track &orig);
 
    virtual ~ Track();
@@ -352,12 +350,6 @@ public:
    virtual void SetPan( float ){ ;}
    virtual void SetPanFromChannelType(){ ;};
 
-   // AS: Note that the project is mutable.  This is
-   // mostly to support "Duplicate" of const objects,
-   // but in general, mucking with the dir manager is
-   // separate from the Track.
-   AudacityProject *GetProject() const { return mProject; }
-
    // Create a NEW track and modify this track
    // Return non-NULL or else throw
    // May assume precondition: t0 <= t1
@@ -716,8 +708,8 @@ protected:
 class AUDACITY_DLL_API AudioTrack /* not final */ : public Track
 {
 public:
-   AudioTrack(AudacityProject *project)
-      : Track{ project } {}
+   AudioTrack()
+      : Track{} {}
    AudioTrack(const Track &orig) : Track{ orig } {}
 
    // Serialize, not with tags of its own, but as attributes within a tag.
@@ -731,8 +723,8 @@ public:
 class AUDACITY_DLL_API PlayableTrack /* not final */ : public AudioTrack
 {
 public:
-   PlayableTrack(AudacityProject *project)
-      : AudioTrack{ project } {}
+   PlayableTrack()
+      : AudioTrack{} {}
    PlayableTrack(const Track &orig) : AudioTrack{ orig } {}
 
    bool GetMute    () const { return mMute;     }
diff --git a/src/WaveTrack.cpp b/src/WaveTrack.cpp
index 37f6440f6..a14604f3b 100644
--- a/src/WaveTrack.cpp
+++ b/src/WaveTrack.cpp
@@ -47,7 +47,6 @@ Track classes.
 #include "Sequence.h"
 #include "Spectrum.h"
 
-#include "Project.h"
 #include "ProjectFileIORegistry.h"
 #include "ProjectSettings.h"
 
@@ -94,8 +93,10 @@ WaveTrack::Holder TrackFactory::NewWaveTrack(sampleFormat format, double rate)
    return std::make_shared<WaveTrack> ( &mProject, format, rate );
 }
 
-WaveTrack::WaveTrack(AudacityProject *project, sampleFormat format, double rate) :
-   PlayableTrack(project)
+WaveTrack::WaveTrack( AudacityProject *project,
+   sampleFormat format, double rate )
+   : PlayableTrack()
+   , mProject(project)
 {
    mLegacyProjectFileOffset = 0;
 
@@ -142,6 +143,8 @@ WaveTrack::WaveTrack(const WaveTrack &orig):
 void WaveTrack::Init(const WaveTrack &orig)
 {
    PlayableTrack::Init(orig);
+   mProject = orig.mProject;
+   
    mFormat = orig.mFormat;
    mWaveColorIndex = orig.mWaveColorIndex;
    mRate = orig.mRate;
diff --git a/src/WaveTrack.h b/src/WaveTrack.h
index a105c69a3..b5b866f35 100644
--- a/src/WaveTrack.h
+++ b/src/WaveTrack.h
@@ -577,6 +577,10 @@ private:
    // Private variables
    //
 
+   // AS: Note that the mProject is mutable.  This is
+   // mostly to support "Duplicate" of const objects
+   mutable AudacityProject *mProject;
+
    wxCriticalSection mFlushCriticalSection;
    wxCriticalSection mAppendCriticalSection;
    double mLegacyProjectFileOffset;