Put the tune you want to learn on a cassette or CD,and make several complete repeats. Put it in your Walkman. Listen to it constantly until you can whistle or "dum ditty" the whole tune in your head. Then go try to play it. (This is the point at which I get out the music to follow along, (and find out where the differences in setting/arrangment) show up, grin). Works pretty well for me. By then, of course, I am so sick of the tune I don't want to play it, but that is another story!