These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
It's quite well known in Salzburg because, well, Money, Dear Boy. Sound of Music Tours are quite popular.
Alternative Character Interpretation: Is Georg left heart-broken and harsh after the death of his first wife, only to be awoken by the beautiful music of his children, or was it because he realized how good a good nanny is for them after firing so many? Or does he warm up as he begins to fall in love with Maria?
Rolfe - oblivious and naive enough to be seduced by the Nazi regime or two-faced bastard?
More likely to be oblivious and naive - consider the average German civilian's reaction to the existence of Auschwitz etc after WWII had finished. This is detailed in documentaries such as The World At War etc.
Big Lipped Alligator Moment: In the movie, "The Lonely Goatherd" was demoted to a one-off puppet show scene after "My Favourite Things" became the song of choice for the thunderstorm scene.note "My Favorite Things" was originally sung by Maria and the Mother Abbess before she left the abbey (the first time).
Designated Villain: The Baroness. In the musical, the only thing she did wrong was be rich, unliked by the children (and even then, only in comparison to Maria), and choosing not to cause any trouble with Germany to save their heads. She was made a little cattier in the movie, but really at worst she was just preventing Maria from moving in on her fiance.
And then there's the live Carrie Underwood show, where many viewers were rooting for her over Maria!
Ear Worm: Several songs from the movie have made their way into pop culture, including "My Favourite Things", "Do-Re-Mi" and "Edelweiss".
Ensemble Darkhorse: The nuns, of course! They dismantled a car to save an Austrian family from the Nazis!
Captain Von Trapp asking her if she was this much trouble in the abbey, to which Maria responds "oh much more sir". The real Maria always joked that the film toned her behaviour in the abbey down - claiming she was much worse.
Liesl asking if she could taste her first champagne at the party, only for her father to say no and send her to bed. Charmian Carr who played Liesl later said that Christopher Plummer taught her how to drink in real life.
Moral Event Horizon: This happens when Liesl's boyfriend Rolfe joins the Third Reich. He threatens to shoot the von Trapps when he catches them trying to escape, but the Captain confiscates the gun and then says:
Captain von Trapp: You'll never be one of them. (beat) Rolfe: (yelling out) LIEUTENANT! LIEUTENANT, THEY'RE HERE! THEY'RE HERE, LIEUTENANT! (blows whistle)
Older Than They Think: In the 2013 live-TV version, the actress playing the Baroness wears some hippie-like bell bottoms for one scene. Despite seeming like a glaring anachronism, it is plausible: bell-bottomed trousers were fashionable for upper-class women in the 1920s and '30s. (They probably weren't "fire-engine red", though.)
Newer Than They Think: "Edelweiss" was written for the musical: it is neither an Austrian folk song nor the Austrian national anthem (as President Reagan believed).