On Christmas Day 1989, shortly after the Berlin Wall fell, Leonard Bernstein gathered together four great choirs, and gave a concert in Berlin celebrating the end of the Wall.
The piece of music chosen for this concert was Beethoven's 9th symphony (Ode to Joy) with the word "Joy" (Freude) changed to "Freedom" (Freiheit) in the lyrics sung. The orchestra and choir were drawn from both East and West Germany, as well as the United Kingdom, France, the Soviet Union, and the United States.
It is, in my opinion, the single greatest recording of the 9th Symphony in existence, especially the 4th movement. If the world were ending and there were just time enough to broadcast one piece of music to the stars so that in some distant future an alien civilization might get a glimpse of what humanity was like.... it would be this recording.
If you have never heard Beethoven's final symphony all the way through, this is the recording to listen to.
Whatever you do, don't leave this world never having heard the 4th movement as expressed by the combined genius of Bernstein and Beethoven. (The 4th movement begins in recording "4a" of the playlist linked here. There are embedded ads, but it's still magnificent)
Ode to Joy and Ode to Freedom.
Enjoy!