The best musical-non-musical director is John Ford, I think. So many good musical moments, but for me two that really stand out:
"Marcheta" in They Were Expendable
. If you don't think John Wayne can make you choke up, watch this movie. The scene of him hearing this song at a dispirited, beaten-down low point of the war and remembering it from happier times -- earlier in the movie, earlier in the world -- is pretty powerful. I can only imagine what it was like to see it in 1945.
"I'll Take You Home Again Kathleen" in Rio Grande
. The John Wayne-Maureen O'Hara chemistry is born. Ken Curtis's pure tenor and the Sons of the Pioneers harmonies may have given an added movie-record "cross-promotion" benefit, but rarely have I seen the lyrics of an existing song used so effectively for a movie's narrative
"It Had to Be You" in Annie Hall
. Not only did it showcase Diane Keaton's pretty voice, but it established that Annie wasn't just a cute and quirky love-interest but had talent and an artistic sensibility of her own.
"Der treue Hussar" in Paths of Glory
. Maybe the most incongruous and at the same time most moving ending to a war movie I've ever seen.
I'll probably think of more.