Very nice sounds. Since you asked for feedback, here is some: * the whole program crashes for me when I pull down the File or Patch menus or try to close the window, with lots of Gtk error messages about invalid style objects. If I change line 241 in gtkknob.c from widget->style = gtk_style_attach(widget->parent->style, widget->window); to widget->style = gtk_style_attach(widget->style, widget->window); it doesn't crash any more. Other behaviour seems to be identical.