I think the first time that I heard this
Pete Seeger song must have been in the mid-1950's as it was then often sung on radio by Marlene Dietrich and I believe it was something of a hit. I enjoy singing it both in German and in English.
The version I sing can be found in
Die Mundorgel, it provides the lyrics both in German and English, the German lyrics being attributed to a certain Max Colpet.
Britta Steenken selected an SAB arrangement of
Where have all the flowers gone to be sung by
Das Trio sometime in 2007. The arrangement by Alan Vincent can be found in
Chor aktuell junior published by
Gustav Bosse Verlag. The bass voice lyrics, my voice, are just a few "Doo doo-doo doo"s followed by 20 bars of "Ah"s needing deep lungs and lots of puff - especially if there is only one bass.