diff --git a/include/audacity/EffectInterface.h b/include/audacity/EffectInterface.h
index 1352a7981..2f22945ea 100755
--- a/include/audacity/EffectInterface.h
+++ b/include/audacity/EffectInterface.h
@@ -98,6 +98,7 @@ public:
 };
 
 class wxDialog;
+class wxWindow;
 class EffectUIHostInterface;
 class EffectUIClientInterface;
 
diff --git a/src/AudacityApp.cpp b/src/AudacityApp.cpp
index c48a71e19..f950edaa0 100644
--- a/src/AudacityApp.cpp
+++ b/src/AudacityApp.cpp
@@ -36,7 +36,6 @@ It handles initialization and termination by subclassing wxApp.
 #include <wx/docview.h>
 #include <wx/event.h>
 #include <wx/ipc.h>
-#include <wx/log.h>
 #include <wx/window.h>
 #include <wx/intl.h>
 #include <wx/menu.h>
@@ -989,8 +988,8 @@ wxString AudacityApp::SetLang( const wxString & lang )
    }
    mLocale = std::make_unique<wxLocale>(info->Language);
 
-   for(unsigned int i=0; i<audacityPathList.size(); i++)
-      mLocale->AddCatalogLookupPathPrefix(audacityPathList[i]);
+   for( const auto &path : FileNames::AudacityPathList() )
+      mLocale->AddCatalogLookupPathPrefix( path );
 
    // LL:  Must add the wxWidgets catalog manually since the search
    //      paths were not set up when mLocale was created.  The
@@ -1266,6 +1265,7 @@ bool AudacityApp::OnInit()
    //
    // Paths: set search path and temp dir path
    //
+   FilePaths audacityPathList;
 
 #ifdef __WXGTK__
    /* Search path (for plug-ins, translations etc) is (in this order):
@@ -1294,36 +1294,36 @@ bool AudacityApp::OnInit()
    wxString pathVar = wxGetenv(wxT("DARKAUDACITY_PATH"));
 #endif
    if (!pathVar.empty())
-      AddMultiPathsToPathList(pathVar, audacityPathList);
-   AddUniquePathToPathList(::wxGetCwd(), audacityPathList);
+      FileNames::AddMultiPathsToPathList(pathVar, audacityPathList);
+   FileNames::AddUniquePathToPathList(::wxGetCwd(), audacityPathList);
 
 #ifdef AUDACITY_NAME
-   AddUniquePathToPathList(wxString::Format(wxT("%s/.%s-files"),
+   FileNames::AddUniquePathToPathList(wxString::Format(wxT("%s/.%s-files"),
       home, wxT(AUDACITY_NAME)),
       audacityPathList);
-   AddUniquePathToPathList(wxString::Format(wxT("%s/share/%s"),
+   FileNames::AddUniquePathToPathList(wxString::Format(wxT("%s/share/%s"),
       wxT(INSTALL_PREFIX), wxT(AUDACITY_NAME)),
       audacityPathList);
-   AddUniquePathToPathList(wxString::Format(wxT("%s/share/doc/%s"),
+   FileNames::AddUniquePathToPathList(wxString::Format(wxT("%s/share/doc/%s"),
       wxT(INSTALL_PREFIX), wxT(AUDACITY_NAME)),
       audacityPathList);
 #else //AUDACITY_NAME
-   AddUniquePathToPathList(wxString::Format(wxT("%s/.audacity-files"),
+   FileNames::AddUniquePathToPathList(wxString::Format(wxT("%s/.audacity-files"),
       home),
       audacityPathList);
-   AddUniquePathToPathList(wxString::Format(wxT("%s/share/audacity"),
+   FileNames::AddUniquePathToPathList(wxString::Format(wxT("%s/share/audacity"),
       wxT(INSTALL_PREFIX)),
       audacityPathList);
-   AddUniquePathToPathList(wxString::Format(wxT("%s/share/doc/audacity"),
+   FileNames::AddUniquePathToPathList(wxString::Format(wxT("%s/share/doc/audacity"),
       wxT(INSTALL_PREFIX)),
       audacityPathList);
 #endif //AUDACITY_NAME
 
-   AddUniquePathToPathList(wxString::Format(wxT("%s/share/locale"),
+   FileNames::AddUniquePathToPathList(wxString::Format(wxT("%s/share/locale"),
       wxT(INSTALL_PREFIX)),
       audacityPathList);
 
-   AddUniquePathToPathList(wxString::Format(wxT("./locale")),
+   FileNames::AddUniquePathToPathList(wxString::Format(wxT("./locale")),
       audacityPathList);
 
 #endif //__WXGTK__
@@ -1346,8 +1346,8 @@ bool AudacityApp::OnInit()
 #ifdef __WXMSW__
    // On Windows, the path to the Audacity program is in argv[0]
    wxString progPath = wxPathOnly(argv[0]);
-   AddUniquePathToPathList(progPath, audacityPathList);
-   AddUniquePathToPathList(progPath + wxT("\\Languages"), audacityPathList);
+   FileNames::AddUniquePathToPathList(progPath, audacityPathList);
+   FileNames::AddUniquePathToPathList(progPath + wxT("\\Languages"), audacityPathList);
 
    // See bug #1271 for explanation of location
    tmpDirLoc = FileNames::MkDir(wxStandardPaths::Get().GetUserLocalDataDir());
@@ -1359,14 +1359,16 @@ bool AudacityApp::OnInit()
    // On Mac OS X, the path to the Audacity program is in argv[0]
    wxString progPath = wxPathOnly(argv[0]);
 
-   AddUniquePathToPathList(progPath, audacityPathList);
+   FileNames::AddUniquePathToPathList(progPath, audacityPathList);
    // If Audacity is a "bundle" package, then the root directory is
    // the great-great-grandparent of the directory containing the executable.
-   //AddUniquePathToPathList(progPath + wxT("/../../../"), audacityPathList);
+   //FileNames::AddUniquePathToPathList(progPath + wxT("/../../../"), audacityPathList);
 
    // These allow for searching the "bundle"
-   AddUniquePathToPathList(progPath + wxT("/../"), audacityPathList);
-   AddUniquePathToPathList(progPath + wxT("/../Resources"), audacityPathList);
+   FileNames::AddUniquePathToPathList(
+      progPath + wxT("/../"), audacityPathList);
+   FileNames::AddUniquePathToPathList(
+      progPath + wxT("/../Resources"), audacityPathList);
 
    // JKC Bug 1220: Using an actual temp directory for session data on Mac was
    // wrong because it would get cleared out on a reboot.
@@ -1379,6 +1381,8 @@ bool AudacityApp::OnInit()
    //   wxGetUserId() ) );
 #endif //__WXMAC__
 
+   FileNames::SetAudacityPathList( std::move( audacityPathList ) );
+
    // Define languanges for which we have translations, but that are not yet
    // supported by wxWidgets.
    //
@@ -2021,54 +2025,6 @@ std::unique_ptr<wxCmdLineParser> AudacityApp::ParseCommandLine()
    return{};
 }
 
-// static
-void AudacityApp::AddUniquePathToPathList(const FilePath &pathArg,
-                                          FilePaths &pathList)
-{
-   wxFileName pathNorm = pathArg;
-   pathNorm.Normalize();
-   const wxString newpath{ pathNorm.GetFullPath() };
-
-   for(unsigned int i=0; i<pathList.size(); i++) {
-      if (wxFileName(newpath) == wxFileName(pathList[i]))
-         return;
-   }
-
-   pathList.push_back(newpath);
-}
-
-// static
-void AudacityApp::AddMultiPathsToPathList(const wxString &multiPathStringArg,
-                                          FilePaths &pathList)
-{
-   wxString multiPathString(multiPathStringArg);
-   while (!multiPathString.empty()) {
-      wxString onePath = multiPathString.BeforeFirst(wxPATH_SEP[0]);
-      multiPathString = multiPathString.AfterFirst(wxPATH_SEP[0]);
-      AddUniquePathToPathList(onePath, pathList);
-   }
-}
-
-// static
-void AudacityApp::FindFilesInPathList(const wxString & pattern,
-                                      const FilePaths & pathList,
-                                      FilePaths & results,
-                                      int flags)
-{
-   wxLogNull nolog;
-
-   if (pattern.empty()) {
-      return;
-   }
-
-   wxFileName ff;
-
-   for(size_t i = 0; i < pathList.size(); i++) {
-      ff = pathList[i] + wxFILE_SEP_PATH + pattern;
-      wxDir::GetAllFiles(ff.GetPath(), &results, ff.GetFullName(), flags);
-   }
-}
-
 void AudacityApp::OnQueryEndSession(wxCloseEvent & event)
 {
    bool mustVeto = false;
diff --git a/src/AudacityApp.h b/src/AudacityApp.h
index b0c91f44a..5fbdcf962 100644
--- a/src/AudacityApp.h
+++ b/src/AudacityApp.h
@@ -20,7 +20,6 @@
 #include "Experimental.h"
 
 #include <wx/app.h> // to inherit
-#include <wx/dir.h> // for wxDIR_FILES
 #include <wx/timer.h> // member variable
 
 #if defined(EXPERIMENTAL_CRASH_REPORT)
@@ -113,26 +112,6 @@ class AudacityApp final : public wxApp {
     void AssociateFileTypes();
    #endif
 
-   /** \brief A list of directories that should be searched for Audacity files
-    * (plug-ins, help files, etc.).
-    *
-    * On Unix this will include the directory Audacity was installed into,
-    * plus the current user's .audacity-data/Plug-Ins directory.  Additional
-    * directories can be specified using the AUDACITY_PATH environment
-    * variable.  On Windows or Mac OS, this will include the directory
-    * which contains the Audacity program. */
-   FilePaths audacityPathList;
-
-   // Useful functions for working with search paths
-   static void AddUniquePathToPathList(const FilePath &path,
-                                       FilePaths &pathList);
-   static void AddMultiPathsToPathList(const wxString &multiPathString,
-                                       FilePaths &pathList);
-   static void FindFilesInPathList(const wxString & pattern,
-                                   const FilePaths & pathList,
-                                   FilePaths &results,
-                                   int flags = wxDIR_FILES);
-
    bool GetWindowRectAlreadySaved()const {return mWindowRectAlreadySaved;}
    void SetWindowRectAlreadySaved(bool alreadySaved) {mWindowRectAlreadySaved = alreadySaved;}
 
diff --git a/src/FileNames.cpp b/src/FileNames.cpp
index 9b197a6a6..16cbe7725 100644
--- a/src/FileNames.cpp
+++ b/src/FileNames.cpp
@@ -519,3 +519,65 @@ bool FileNames::IsTempDirectoryNameOK( const FilePath & Name )
 #endif
    return !(NameCanonical.StartsWith( BadPath ));
 }
+
+static FilePaths sAudacityPathList;
+
+const FilePaths &FileNames::AudacityPathList()
+{
+   return sAudacityPathList;
+}
+
+void FileNames::SetAudacityPathList( FilePaths list )
+{
+   sAudacityPathList = std::move( list );
+}
+
+// static
+void FileNames::AddUniquePathToPathList(const FilePath &pathArg,
+                                          FilePaths &pathList)
+{
+   wxFileNameWrapper pathNorm { pathArg };
+   pathNorm.Normalize();
+   const wxString newpath{ pathNorm.GetFullPath() };
+
+   for(const auto &path : pathList) {
+      if (pathNorm == wxFileNameWrapper{ path })
+         return;
+   }
+
+   pathList.push_back(newpath);
+}
+
+// static
+void FileNames::AddMultiPathsToPathList(const wxString &multiPathStringArg,
+                                          FilePaths &pathList)
+{
+   wxString multiPathString(multiPathStringArg);
+   while (!multiPathString.empty()) {
+      wxString onePath = multiPathString.BeforeFirst(wxPATH_SEP[0]);
+      multiPathString = multiPathString.AfterFirst(wxPATH_SEP[0]);
+      AddUniquePathToPathList(onePath, pathList);
+   }
+}
+
+#include <wx/log.h>
+
+// static
+void FileNames::FindFilesInPathList(const wxString & pattern,
+                                      const FilePaths & pathList,
+                                      FilePaths & results,
+                                      int flags)
+{
+   wxLogNull nolog;
+
+   if (pattern.empty()) {
+      return;
+   }
+
+   wxFileNameWrapper ff;
+
+   for(size_t i = 0; i < pathList.size(); i++) {
+      ff = pathList[i] + wxFILE_SEP_PATH + pattern;
+      wxDir::GetAllFiles(ff.GetPath(), &results, ff.GetFullName(), flags);
+   }
+}
diff --git a/src/FileNames.h b/src/FileNames.h
index 16c7851cb..b1ae52024 100644
--- a/src/FileNames.h
+++ b/src/FileNames.h
@@ -13,6 +13,7 @@
 
 #include "Audacity.h"
 
+#include <wx/dir.h> // for wxDIR_FILES
 #include <wx/string.h> // function return value
 #include "audacity/Types.h"
 
@@ -40,6 +41,17 @@ public:
    static void SetDefaultTempDir( const FilePath &tempDir );
    static bool IsTempDirectoryNameOK( const FilePath & Name );
 
+   /** \brief A list of directories that should be searched for Audacity files
+    * (plug-ins, help files, etc.).
+    *
+    * On Unix this will include the directory Audacity was installed into,
+    * plus the current user's .audacity-data/Plug-Ins directory.  Additional
+    * directories can be specified using the AUDACITY_PATH environment
+    * variable.  On Windows or Mac OS, this will include the directory
+    * which contains the Audacity program. */
+   static const FilePaths &AudacityPathList();
+   static void SetAudacityPathList( FilePaths list );
+
    // originally an ExportMultiple method. Append suffix if newName appears in otherNames.
    static void MakeNameUnique(
       FilePaths &otherNames, wxFileName &newName);
@@ -123,6 +135,16 @@ public:
                 int flags,
                 wxWindow *parent);
 
+   // Useful functions for working with search paths
+   static void AddUniquePathToPathList(const FilePath &path,
+                                       FilePaths &pathList);
+   static void AddMultiPathsToPathList(const wxString &multiPathString,
+                                       FilePaths &pathList);
+   static void FindFilesInPathList(const wxString & pattern,
+                                   const FilePaths & pathList,
+                                   FilePaths &results,
+                                   int flags = wxDIR_FILES);
+
 private:
    // Private constructors: No one is ever going to instantiate it.
    //
diff --git a/src/Languages.cpp b/src/Languages.cpp
index becd2f273..0c70e9d34 100644
--- a/src/Languages.cpp
+++ b/src/Languages.cpp
@@ -32,6 +32,7 @@
 
 #include "Audacity.h"
 #include "Languages.h"
+#include "MemoryX.h"
 
 #include "audacity/Types.h"
 
@@ -41,8 +42,6 @@
 
 #include "FileNames.h"
 
-#include "AudacityApp.h"
-
 #include <unordered_map>
 
 using LangHash = std::unordered_map<wxString, wxString>;
@@ -50,18 +49,18 @@ using LangHash = std::unordered_map<wxString, wxString>;
 static bool TranslationExists(const FilePaths &audacityPathList, wxString code)
 {
    FilePaths results;
-   wxGetApp().FindFilesInPathList(wxString::Format(wxT("%s/audacity.mo"),
+   FileNames::FindFilesInPathList(wxString::Format(wxT("%s/audacity.mo"),
                                                    code),
                                   audacityPathList,
                                   results);
 #if defined(__WXMAC__)
-   wxGetApp().FindFilesInPathList(wxString::Format(wxT("%s.lproj/audacity.mo"),
+   FileNames::FindFilesInPathList(wxString::Format(wxT("%s.lproj/audacity.mo"),
                                                    code),
                                   audacityPathList,
                                   results);
 #endif
 
-   wxGetApp().FindFilesInPathList(wxString::Format(wxT("%s/LC_MESSAGES/audacity.mo"),
+   FileNames::FindFilesInPathList(wxString::Format(wxT("%s/LC_MESSAGES/audacity.mo"),
                                                    code),
                                   audacityPathList,
                                   results);
@@ -203,12 +202,13 @@ void GetLanguages(wxArrayString &langCodes, wxArrayString &langNames)
       localLanguageName[code] = name;
    }
 
-   auto audacityPathList = wxGetApp().audacityPathList;
+   auto audacityPathList = FileNames::AudacityPathList();
 
 #if defined(__WXGTK__)
-   wxGetApp().AddUniquePathToPathList(wxString::Format(wxT("%s/share/locale"),
-                                                       wxT(INSTALL_PREFIX)),
-                                      audacityPathList);
+   FileNames::AddUniquePathToPathList(
+      wxString::Format(wxT("%s/share/locale"),
+         wxT(INSTALL_PREFIX)),
+      audacityPathList);
 #endif
 
    // For each language in our list we look for a corresponding entry in
diff --git a/src/ModuleManager.cpp b/src/ModuleManager.cpp
index e21a03caf..b26cca80e 100755
--- a/src/ModuleManager.cpp
+++ b/src/ModuleManager.cpp
@@ -28,7 +28,6 @@ i.e. an alternative to the usual interface, for Audacity.
 #include <wx/string.h>
 #include <wx/filename.h>
 
-#include "AudacityApp.h"
 #include "FileNames.h"
 #include "PluginManager.h"
 
@@ -212,7 +211,7 @@ ModuleManager::~ModuleManager()
 // static 
 void ModuleManager::Initialize(CommandHandler &cmdHandler)
 {
-   const auto &audacityPathList = wxGetApp().audacityPathList;
+   const auto &audacityPathList = FileNames::AudacityPathList();
    FilePaths pathList;
    FilePaths files;
    wxString pathVar;
@@ -221,18 +220,18 @@ void ModuleManager::Initialize(CommandHandler &cmdHandler)
    // Code from LoadLadspa that might be useful in load modules.
    pathVar = wxGetenv(wxT("AUDACITY_MODULES_PATH"));
    if (!pathVar.empty())
-      wxGetApp().AddMultiPathsToPathList(pathVar, pathList);
+      FileNames::AddMultiPathsToPathList(pathVar, pathList);
 
    for (i = 0; i < audacityPathList.size(); i++) {
       wxString prefix = audacityPathList[i] + wxFILE_SEP_PATH;
-      wxGetApp().AddUniquePathToPathList(prefix + wxT("modules"),
+      FileNames::AddUniquePathToPathList(prefix + wxT("modules"),
                                          pathList);
    }
 
    #if defined(__WXMSW__)
-   wxGetApp().FindFilesInPathList(wxT("*.dll"), pathList, files);
+   FileNames::FindFilesInPathList(wxT("*.dll"), pathList, files);
    #else
-   wxGetApp().FindFilesInPathList(wxT("*.so"), pathList, files);
+   FileNames::FindFilesInPathList(wxT("*.so"), pathList, files);
    #endif
 
    wxString saveOldCWD = ::wxGetCwd();
@@ -357,19 +356,19 @@ bool ModuleManager::DiscoverProviders()
 
    if (!pathVar.empty())
    {
-      wxGetApp().AddMultiPathsToPathList(pathVar, pathList);
+      FileNames::AddMultiPathsToPathList(pathVar, pathList);
    }
    else
    {
-      wxGetApp().AddUniquePathToPathList(FileNames::ModulesDir(), pathList);
+      FileNames::AddUniquePathToPathList(FileNames::ModulesDir(), pathList);
    }
 
 #if defined(__WXMSW__)
-   wxGetApp().FindFilesInPathList(wxT("*.dll"), pathList, provList);
+   FileNames::FindFilesInPathList(wxT("*.dll"), pathList, provList);
 #elif defined(__WXMAC__)
-   wxGetApp().FindFilesInPathList(wxT("*.dylib"), pathList, provList);
+   FileNames::FindFilesInPathList(wxT("*.dylib"), pathList, provList);
 #else
-   wxGetApp().FindFilesInPathList(wxT("*.so"), pathList, provList);
+   FileNames::FindFilesInPathList(wxT("*.so"), pathList, provList);
 #endif
 
    PluginManager & pm = PluginManager::Get();
diff --git a/src/effects/nyquist/LoadNyquist.cpp b/src/effects/nyquist/LoadNyquist.cpp
index 16bf8e849..881c31369 100644
--- a/src/effects/nyquist/LoadNyquist.cpp
+++ b/src/effects/nyquist/LoadNyquist.cpp
@@ -8,7 +8,6 @@
 
 **********************************************************************/
 
-#include "../../AudacityApp.h"
 #include "LoadNyquist.h"
 
 #include <wx/log.h>
@@ -129,7 +128,7 @@ wxString NyquistEffectsModule::GetDescription()
 
 bool NyquistEffectsModule::Initialize()
 {
-   const auto &audacityPathList = wxGetApp().audacityPathList;
+   const auto &audacityPathList = FileNames::AudacityPathList();
 
    for (size_t i = 0, cnt = audacityPathList.size(); i < cnt; i++)
    {
diff --git a/src/effects/nyquist/Nyquist.cpp b/src/effects/nyquist/Nyquist.cpp
index 0f4ce058c..2fd25c8b8 100644
--- a/src/effects/nyquist/Nyquist.cpp
+++ b/src/effects/nyquist/Nyquist.cpp
@@ -2350,15 +2350,15 @@ void NyquistEffect::OSCallback()
 
 FilePaths NyquistEffect::GetNyquistSearchPath()
 {
-   const auto &audacityPathList = wxGetApp().audacityPathList;
+   const auto &audacityPathList = FileNames::AudacityPathList();
    FilePaths pathList;
 
    for (size_t i = 0; i < audacityPathList.size(); i++)
    {
       wxString prefix = audacityPathList[i] + wxFILE_SEP_PATH;
-      wxGetApp().AddUniquePathToPathList(prefix + wxT("nyquist"), pathList);
-      wxGetApp().AddUniquePathToPathList(prefix + wxT("plugins"), pathList);
-      wxGetApp().AddUniquePathToPathList(prefix + wxT("plug-ins"), pathList);
+      FileNames::AddUniquePathToPathList(prefix + wxT("nyquist"), pathList);
+      FileNames::AddUniquePathToPathList(prefix + wxT("plugins"), pathList);
+      FileNames::AddUniquePathToPathList(prefix + wxT("plug-ins"), pathList);
    }
    pathList.push_back(FileNames::PlugInDir());
 
diff --git a/src/wxFileNameWrapper.h b/src/wxFileNameWrapper.h
index 922c72eb0..078532c3d 100644
--- a/src/wxFileNameWrapper.h
+++ b/src/wxFileNameWrapper.h
@@ -20,7 +20,9 @@ class wxArrayString;
 class wxFileNameWrapper : public wxFileName
 {
 public:
-   explicit
+     using wxFileName::wxFileName;
+
+     explicit
       wxFileNameWrapper(const wxFileName &that)
       : wxFileName(that)
    {}