Okay, I'm looking at my sheet music for "Carol of the Bells" - words by Peter J. Wilhousky, music by M. Leontovich arr. by Peter J. Wilhousky, copyright 1936 by Carl Fischer, Inc. New York (this particular music is arranged for SATB, which I was told stands for "Sing America The Beautiful", though it may also have something to do with Soprano Alto Tenor Bass :) .)

This version does indeed have "Ding Dong Ding Dong" rather than "Ding Dong Ding", and it also has "song of good cheer" rather than "songs of good cheer".

I make no claim that this is the *definitive* version. I would argue for "Ding Dong Ding Dong" on the grounds that 1) "dong" rhymes with "song", and 2) "Ding Dong Ding Dong" has the same number of syllables as "Hark! how the bells". But "song of good cheer" sounded wrong to me when my group was learning the piece, since I had always heard "songs" before. Folk process?

Don