Let's be explicit: Demonstration should act like an attract screen. (This usually

happens to work without this, because the previous attract screen will set it,
and won't unset it since that's done in input.)

stepmania/src/ScreenDemonstration.cpp

@@ -21,6 +21,7 @@ ScreenDemonstration::ScreenDemonstration( CString sName ) : ScreenJukebox( sName
 {
 	LOG->Trace( "ScreenDemonstration::ScreenDemonstration()" );
 	m_bDemonstration = true;
+	SOUNDMAN->SetPlayOnlyCriticalSounds( GAMESTATE->IsTimeToPlayAttractSounds() );  // mute attract sounds
 }
 
 void ScreenDemonstration::Init()