Kenyon Hopkins's soundtrack to 12 Angry Men never came out commercially, but check out this link if you want to give it a listen on its own. As you can probably tell, the music is pretty light and typical for a 1950s movie. But it also does a great job at setting the stage for the beginning and end of the film. At the beginning, the music sounds a little sad, especially when we get a shot of the eighteen year-old kid on trial with tears rolling down his cheeks. At the end of the movie, though, this same sort of music sounds uplifting, because we know that Juror #8 and social justice in general have won the day.