diff --git a/stepmania/src/NoteDataUtil.cpp b/stepmania/src/NoteDataUtil.cpp
index 7106651772..cf93e41bab 100644
--- a/stepmania/src/NoteDataUtil.cpp
+++ b/stepmania/src/NoteDataUtil.cpp
@@ -334,6 +334,8 @@ void NoteDataUtil::LoadTransformedSlidingWindow( const NoteData &in, NoteData &o
 
 	out.SetNumTracks( iNewNumTracks );
 
+	if( in.GetNumTracks() == 0 )
+		return;	// nothing to do and don't AV below
 
 	int iCurTrackOffset = 0;
 	int iTrackOffsetMin = 0;
@@ -1842,6 +1844,22 @@ void NoteDataUtil::RemoveAllTapsExceptForType( NoteData& ndInOut, TapNote::Type
 	}
 }
 
+int NoteDataUtil::GetNumUsedTracks( const NoteData& in )
+{
+	for( int t=0; t<in.GetNumTracks(); t++ )
+	{
+		bool bHasAnyTapsInTrack = false;
+		FOREACH_NONEMPTY_ROW_IN_TRACK( in, t, row )
+		{
+			bHasAnyTapsInTrack = true;
+			break;
+		}
+		if( !bHasAnyTapsInTrack )
+			return t;
+	}
+	return in.GetNumTracks();
+}
+
 
 /*
  * (c) 2001-2004 Chris Danford, Glenn Maynard
diff --git a/stepmania/src/NoteDataUtil.h b/stepmania/src/NoteDataUtil.h
index 1cddc20c04..1f324d5988 100644
--- a/stepmania/src/NoteDataUtil.h
+++ b/stepmania/src/NoteDataUtil.h
@@ -104,6 +104,8 @@ namespace NoteDataUtil
 
 	void RemoveAllTapsOfType( NoteData& ndInOut, TapNote::Type typeToRemove );
 	void RemoveAllTapsExceptForType( NoteData& ndInOut, TapNote::Type typeToKeep );
+
+	int GetNumUsedTracks( const NoteData& in );
 };
 
 #endif
diff --git a/stepmania/src/ScreenEdit.cpp b/stepmania/src/ScreenEdit.cpp
index 4ecb006852..bdad8a187a 100644
--- a/stepmania/src/ScreenEdit.cpp
+++ b/stepmania/src/ScreenEdit.cpp
@@ -386,7 +386,7 @@ static Menu g_AreaMenu(
 	MenuRow( ScreenEdit::quantize,				"Quantize",							true, true, 0, "4th","8th","12th","16th","24th","32nd","48th","64th","192nd"),
 	MenuRow( ScreenEdit::turn,					"Turn",								true, true, 0, "Left","Right","Mirror","Shuffle","SuperShuffle" ),
 	MenuRow( ScreenEdit::transform,				"Transform",						true, true, 0, "NoHolds","NoMines","Little","Wide","Big","Quick","Skippy","Mines","Echo","Stomp","Planted","Floored","Twister","NoJumps","NoHands","NoQuads" ),
-	MenuRow( ScreenEdit::alter,					"Alter",							true, true, 0, "Backwards","Swap Sides","Copy Left To Right","Copy Right To Left","Clear Left","Clear Right","Collapse To One","Collapse Left","Shift Left","Shift Right" ),
+	MenuRow( ScreenEdit::alter,					"Alter",							true, true, 0, "Autogen To Fill Width","Backwards","Swap Sides","Copy Left To Right","Copy Right To Left","Clear Left","Clear Right","Collapse To One","Collapse Left","Shift Left","Shift Right" ),
 	MenuRow( ScreenEdit::tempo,					"Tempo",							true, false, 0, "Compress 2x","Compress 3->2","Compress 4->3","Expand 3->4","Expand 2->3","Expand 2x" ),
 	MenuRow( ScreenEdit::play,					"Play selection",					true, true, 0, NULL ),
 	MenuRow( ScreenEdit::record,				"Record in selection",				true, true, 0, NULL ),
@@ -2132,6 +2132,15 @@ void ScreenEdit::HandleAreaMenuChoice( AreaMenuChoice c, const vector<int> &iAns
 				AlterType at = (AlterType)iAnswers[c];
 				switch( at )
 				{
+				case autogen_to_fill_width:	
+					{
+						NoteData temp( m_Clipboard );
+						int iNumUsedTracks = NoteDataUtil::GetNumUsedTracks( temp );
+						temp.SetNumTracks( iNumUsedTracks );
+						NoteDataUtil::LoadTransformedSlidingWindow( temp, m_Clipboard, m_Clipboard.GetNumTracks() );
+						NoteDataUtil::FixImpossibleRows( m_Clipboard, GAMESTATE->m_pCurSteps[0]->m_StepsType );
+					}
+					break;
 				case backwards:				NoteDataUtil::Backwards( m_Clipboard );			break;
 				case swap_sides:			NoteDataUtil::SwapSides( m_Clipboard );			break;
 				case copy_left_to_right:	NoteDataUtil::CopyLeftToRight( m_Clipboard );	break;
diff --git a/stepmania/src/ScreenEdit.h b/stepmania/src/ScreenEdit.h
index ce34848ea0..bfcd08e65f 100644
--- a/stepmania/src/ScreenEdit.h
+++ b/stepmania/src/ScreenEdit.h
@@ -293,7 +293,8 @@ public:
 		NUM_TRANSFORM_TYPES 
 	};
 	enum AlterType 
-	{ 
+	{
+		autogen_to_fill_width,
 		backwards, 
 		swap_sides, 
 		copy_left_to_right,