Variations to VENI EMMANUEL

I don't know for sure what you mean by the variant that "runs straight through", but my guess is that it's just a notation event that's closer to typical chant notation. Chant notation is frequently all quarter notes without stems, which looks pretty hard to sing, but chant practice tends to allow for a more speechlike variation in cadence, with appropriate pauses even though they are not notated. People used to liturgical chant (Catholics, Episcopalians, ... ) will find it quite doable, while others may be completely incapacitated by it. The actual singing is probably not all that different. The VENI EMMANUEL tune is descended from a chant-oriented ecclesial culture. The text of the hymn is closely related to the Great O Antiphons, which would certainly have been chanted in their original monastic context. Just a guess. I used to attend an Episcopal church (St. Paul's in Seattle) fairly frequently, and found that a few weeks exposure to chant made it much easier to follow and participate in. My guess is that digging around in YouTube or a similar venue would turn up example of the chanted approach to this tune that would help clarify it to you; but I haven't done the digging involved. If you do, let us know if you found anything helpful.