The variant of the Volga Boatmen/Birthday song I know goes :
Happy Birthday HUUUHH!
Oh, Happy Birthday HUUUHH!
Smoke and smog fill the air
People dying everywhere
Happy Birthday HUUUHH!
Oh, Happy Birthday HUUUHH!

And I've heard a number of other verses on that theme. I think they may be in the Forum someplace, if someone wants to search.

And if you want to count less-serious, doesn't-shove-your-guts-out-your-mouth type "HUHs", there's always,
"Oh, I wanna be a dog, HUH, HUH, HUH, HUH,
Oh, I wanna lie around, HUH, HUH, HUH, HUH
I wanna scratch fleas, and pee on trees,
I just wanna be a hound

I don't see it in the database, but it's in Rise Up Singing.

There is also a singer I sing with regularly at the pub who has raised the art of 'but-saying' to a high level; Whenever the word 'but' appears in his song, BUT especially at the beginning of a line, he belts it out with enough force to remove paint from the walls and cause his adjacent companions to spill or spew their beer. Do you suppose it's relevant to say he's English?
Blessings,
Barbara