$tracker_window =  MainWindow->new..
  $TrackBook = $tracker_window->NoteBook..
  $TrackTabs{'Tracks'} = $TrackBook..
  $Matrix = $TrackTabs{'Tracks'}->Scrolled..  
  $canvas = $Mainwin->Scrolled('Canvas')->grid..
  my $real = $canvas->Subwidget("canvas"); # for bindings..
  $CstObj->{'matrix'}->windowConfigure( "$i,1", -window => $canvas )..