Prepare to have your mind blown, this is something very bizzare you have probably never seen or even thought about before. I'm probably going to sound extremely stupid.
This song (music, to be precise) was made long before my birth, in a country that doesn't exist anymore. Imagine - millions of people dreamt of a beautiful bright future, and their hope and energy was fused into this music. Everything good they were going to build, everything positive they made, all concentrated to be the inspiration for the next generations. And then, after just a few years, all the hopes were destroyed completely. I never really cry, but this makes tears pour from my eyes every time.
Lennauchfilm, "Sulfur", 1984, USSR. Song is located at 8:45 and 18:17.
Soviet documentaries are a standalone form of art.