My last post comparing the 2013 stage version (Live!) with the 1965 movie version was based more on performance differences than script content.
I want to add a bit more on the storyline. The movie makes a number of subtle changes and a few clear plot changes in the stage script.
1. The Baroness. In the movie she is a self-centered conniver and somewhat mean-spirited. She plans to get rid of the children by sending them to boarding school as soon as possible after she and the Captain are married. She also confronts Maria with Maria's love for the Captain and the Captain's love for Maria in order to push Maria into emotional crisis which causes Maria to leave.
In Live! Elsa does neither of the above. She is much more personally appealing. The sort of person the Captain might really be interested in. The break up between Elsa and the Captain comes because Elsa values self-interest and compromise even with the Nazis. The Captain despises the Nazis and will not compromise with them. They both realize this difference is a marriage deal breaker.
2. Rolfe. In the movie Rolfe betrays the family to his Nazi superiors when they are hiding in the abbey. Just before the Captain and Maria's return from their honeymoon he shows himself much more interested in serving with the Nazis than seeing Liesl privately. How that change occurred from the young man who is deeply in love and sings "Sixteen Going on Seventeen" is never explained.
In Live! Rolfe starts to betray the family in the abbey, but when he sees Liesl, he can't go through with it. This is much more in line with the character of a young man in love who is torn between young love and the lure of serving with the Nazis.
3. Maria. At the end of the movie Maria is basically a follower. She has almost no initiative. The Captain makes all the important decisions including the need for the family to flee and that the children can make it over the mountain. She does plead with Herr Zeller that the night air is not good for the children's voices and helps the children keep calm and quiet, but that's about it.
In Live! the Captain also comes to the fore, but Maria has some important input. First, she interposes with the Nazi delegation to suggest that the Captain cannot go immediately to accept his commission with the Nazis because he needs to sing with the family at the festival. Further, when the Captain is unsure about whether the children can make it over the mountain, Maria encourages him that they can make it. The Live! Maria shows some of her leadership skills and strong character in the last part of the play even though the Captain dominates in action and decision making.
4. The Mother Abbess. Not much difference here, but because Maria and the Mother Abbess sing "My Favorite Things" as a duet, Live! gives the bit of information that the Mother Abbess was also raised on the mountain and shows a more complex person who has a fun side along with her seriousness and spiritual devotion.
Most of the changes that the movie made from the play script were for the worse in terms of character development and plot line.
In general terms, the movie is superior on showing more development of the children's character (their playing with the Baroness after Maria has left and visit to the abbey to try to see Maria) and more development in the romance between the Captain and Maria when he declares his love to her. It also has the gorgeous Austrian scenery. And, of course, it has the great Julie Andrews.
Live! has the stunning photography of high-definition video even though it is trained on stage sets rather than real Austrian natural beauty. And, of course, it has the up and coming Carrie Underwood.