The Sound of Music. No-brainer—it's a movie musical, adapted from a Broadway musical. Where would the world be if Maria hadn't taught the kids their musical notes via "Do-Re-Mi"?
We don't even want to think about it.
The film's musical numbers comment on the action and push the story forward. Some of the musical numbers are traditional musical film "bursting into song out of the blue" moments, and others are meant to be actual performances that the characters present.
There's drama here, too. Even in the midst of the movie's aggressive buoyancy and beautiful music, there's trouble brewing. The Nazis are about to march into Austria and make it disappear into Germany. The von Trapp family is faced with the decision of remaining and serving the new regime vs. getting out while they can. That's conflict, and conflict is the beating heart of drama.
We'd say the movie is still pretty solidly a lighthearted musical romp, but the dramatic storyline gives The Sound of Music some heft that many classic musicals don't have—and Shmoop likes it that way.