The original version of Angels at Dawn can be found at the end of my song led Ghyschur (Angels at Dawn) in the al NoyxX Eklypce.
All the timing down to the second mirrors the story leading up to the dropping of the atomic bomb. From children playing (Drop site was just above a children's school). The dialect is actually Chineses. I could not find recordings of Japanese children playing in the public domain.
The planes flying in as you can hear.
The "Angels at Dawn" name is sad if you really break down what color the Enola Gay looked like underneath at dawn (8am - The plane was silver - shined like an angel along with the other planes)
Follow the lyrics of Twinkle Twinkle Little Star and that too has a lot of imagery behind it.
The rise is like where everyone is looking up and wondering about this plane/angel and then silence. The silence and ambiance to the end of the track is 54 seconds and that is exactly how long it took for the bomb to drop to detonation site.