What's a composer to do? I thought I was expressing the text of O Gracious Dwelling. Was I really writing "I bind unto myself today..." . My head is swirling.

You were writing a hymn tune. Period.

... the same text to different tunes, even within the same hymnal

Of course they do, and justifiably so. The same text may be commonly known to different tunes in different communities or regions.

Here are a few multiple tune texts for the current season:

"Lo! he comes with clouds descending" - ST THOMAS & HELMSLEY.

"O little town of Bethlehem" - FOREST GREEN & ST LOUIS.

"It came upon the midnight clear" - CAROL & NOEL.

"Away in a manger" - CRADLE SONG & MUELLER, among many others. See Not So Far Away In A Manger ~ FORTY-ONE SETTINGS OF AN AMERICAN CAROL By Richard S. Hill, Music Library Association "Notes" ~ December, 1945 ~ Second Series, Vol. III, No. 1.

The split page format was/is(?) quite common in Scottish metrical psalters. To some the idea of willy-nilly exchange of tune-text might be appealing. To our major hymnal producers it is a lucrative (as in mendacious) feature that appeals to those who just can't (as in won't, meaning 'absolutely will refuse to') learn to sing more than a dozen tunes. There are just so many texts to which one can sing, say, Abbot's Leigh, Forest Green, Down Ampney, In Babilone, et al., without ruining their special character, not to mention the special character of the hymn text itself. 'O come, all ye faithful' and 'Now thank we all our God' are not the only hymns that would sound quite ridiculous sung to other than their culturally ingrained tunes. Sometimes there may be good reasons for singing an alternate tune (for instance, when the hymn and tune really are not a good match, or one wishes to cast the hymn in a different light), but as a rule it is not a good idea to change tunes for no other silly reason than that one can't be bothered to teach it to his people, or his people themselves have a childish aversion to learning tunes they haven't yet learnt. We have forty years of bad habits, bad attitudes, and cultural idiocy to overcome. There is not a moment to lose.

Quite a few were written to be paired with a given hymn. Many, though (just like the repertory of chant hymn tunes) are just a part of the patrimony of tunes, some of which have become identified with given texts, while others sort of go begging. It is true that some tunes, such as Duke Street, work well with several texts (i.e., 'Jesus shall reign...' & 'I know that my redeemer...' and is not culturally identified with any of them in the way that Adeste fideles is with 'O come...'. You have written a tune with a specific hymn in mind, so, respecting both your and the author's intent, it should remain wedded to that text. That is not to say that it may not, upon careful aesthetical examination, be well sung to another text. As a rule, though, when changing tunes and texts around, one should have serious musical and literary reasons for doing so. 'Nobody knows this tune' is not such a reason. This is exactly like saying that we can't learn a new text because our people haven't sung it before and can't read the words. Absurd!

Almost all hymn tunes and texts languish. You are bearing children for the slaughter.

The mean streets of hymnody.

Just kidding. It's a crowded field, though, even without the strange market forces currently in play.