Bert, see if you can find "Gypsy", the made-for-TV version, with Bette Midler(it is true to the stage version, which is what is often not true of with movie musicals)

You will not get a good of what makes a good show song from watching a Movie musical--you have to see how it plays to an audience--and you can only do this by going to see musicals--

The other thing is that show tunes have to advance the story of the play in some way, and be entertaining, amusing, and often danceable at the same time--big order--

If you are serious about writing show songs, you have to see shows all the time. That means all the local companies, touring companies, and of course, it is necessary to make the supreme sacrifice and go to New York or London, which is the best place to see shows anymore, once or twice every year(easy if you live near either one)--

If you want, feel free to send me a private message so we can talk. I been working on the music a show for several years, and have the story ideas for a couple others--I am at am impasse, but never am at loss for something to say--