"Ei wrote the lyrics while walking home from a Japanese student demonstration protesting against a continued US military presence in the country, expressing his

"Ei wrote the lyrics while walking home from a Japanese student demonstration protesting against a continued US military presence in the country, expressing his frustration at the failed efforts." "An instrumental version of the song was played by NASA over the radio for the Gemini VII astronauts as mood music, thereby becoming one of the first pieces of music sent to humans in space."