I sing bass in several choirs, and quite a few of the bass parts involve us going dm dm dm, or do do do, or something similar. Until recently I thought it was just meaningless sounds we were making, and that maybe the composers / arrangers of the songs just couldn’t be bothered to write words for us basses.
Now I can exclusively reveal here that I have uncovered the Secret Language of Basses. They are not in fact meaningless sounds, but actually hidden messages in Morse Code.
Alternatively they might be in a secret constructed language known only to a few composers.