I love unusual meters. But I have found that most people including many musicians find them difficult. We used to do 2nd Chapter's Easter Song which is in 3/8 but has the occasional 5/8 bar thrown in for good measure. (pun intentional) It gave our drummer fits.
For years I have tried to write a good worship tune in a 5/8 or 7/8 time but it has so far come out too cerebral or odd to promote congregational worship. And that is the main purpose of worship music - to draw the people into focusing on the Lord and not the music.
If you are inspired to write a song like that then do it. Try it out on your congregation. If they can sing it then great. Don't bother second guessing what might not work.
Actually I have written several choruses in alternate meter over the years that I eventually abandoned as they just did not work. And if they don't work for me, (able to play in odd measure) I cannot imagine them working for a congregation lacking in formal music training.
I think something that has been misunderstood is that singing = worship.
I do not confuse that issue. Singing is only the vehicle to allow worship. But as such, if people struggle with the music, it impedes worship; not unlike if a truck is caught in traffic or has a breakdown, the payload will either be late or never show up to its destination.
Almost everyone sings "How Great Thou Art" adding two beats here and there to give it more space, and no one seems to mind. "A Mighty Fortress", in its original version (still preferred in the Lutheran Hymnal), is in mixed metre (or unmetred), which whose measures go 3 , 3, 4, 4, 3, 3, 4, 4 beats, to begin with. As styles changed (or cultures collided, hard to say), the song got dumbed down (within a couple of centuries) to the stiff, stilted 4/4 generally sung today. Same with Joyful, Joyful, Beethoven's tune (of course, Beethoven was considered ghastly by critics, who were offended by his free use of metres and syncopation). I think most of us could use some horizon-expanding. Ordinary musicians in Venezuela think nothing of 11/8, 5/4, and other multifaceted metres.
But - you need poetry that supports these metres. Can't just slap anything on there; but a well-written song transcends traditional metres, chord structures, and styles. Well-written music creates styles, and engenders new visions of beauty.
I am not sure I would call the rise of Baroque "dumbing down" anything. German Baroque was characterized by an ultra-precision clockwork metre; which had it culmination in JS Bach, Georg Tellemann and their contemporaries. Whatever may have been lost in metric diversity was more than made up for in harmonic and rthymic complexity.
J.S. Bach's Fantasia in G Minor is ultra-precision clockwork? Huh? And, to boot, JSB was always in trouble with his church board/city council over playing in a way that was hard to sing with. For that reason, try playing Buxtehude's works with total-precise timing. You will lose 70% of the music.
Of course, the JSB Fantasies were freely rendered. Playing hints given in CPE Bach's Essay, which I wish I had obtained in college, because it is now $42 on amazon. The essay is not limited to Emmanuel's own playing, but to keyboard music in general; he does not make then/now comparisons so much as to distinguish between the freer forms -- 1) the "recitative", the text-delivering song, which is expressive singing punctuated by chords ("a voiiiiiice, crying in the wiiiilderness / prepareyethe way---- of the Lord! [plunk - plunk]), 2) the song ("aria"), in which the bass keeps a relatively steady beat, while the soloist moves in front or behind at his/her pleasure (like today's ballad singers, such as Adele), or 3) contrapuntal music, which, requiring more synchronization of parts, naturally would keep a steady beat, though even the fugues become too "dry" if the parts are too precise. Of course, there are schools of thought on interpretation, and no ultimate conclusion of the matter, since JSB died in 1750, CPE in 1788, the metronome was patented in 1815, and recording devices not until the late 1800's. If you want a trip, listen to various recordings of the same Bach piece - Artur Schnabel (ca. 1930), Svatislov Richter, Rosalyn Tureck, Glenn Gould - you'll hear a lot of rhythmic and dynamic variation.
But as you say, JS Bach, favoring the dense contrapuntal texture, usually uses a strict rhythm (though not likely as strict as in today's metronome-dictator-controlled society). You'll see in some of his later organ pieces (Eb "St. Anne") Prel. & Fugue, say), and in the B Minor Mass, attempts to make the "return to A theme" characteristic of the newer style of the 1740's. Sometimes he's successful, sometimes it's kind of pitiful -- he just kind of jams the A section in there and ends the piece, like a great home run hitter trying to bunt.
And David, these are just my observations - some of these old pieces I started learning when I was twelve, and still (at 64) am undecided as to how to present them! The other day, I went hog-wild on the Toccata in F, and my wife said, "that's the best I've ever heard you play that", though there were hundreds of errors, and times I couldn't even insert some of the inner parts at all -- but the music, the plan, the vision, the structure, the power, the passion, the love came through. If you play Bach too exactly, you can't hear the structure (as with Beethoven). A recording of it would have been a failure; but live was something else (indeed, recording artists are almost a different breed than performing artists). But I kind of get verbal on Bach - hope I haven't stepped on your toes - just really presenting my own thoughts seasoned with the bits and pieces garnered from various sources over the years. And new artists come with new insights - I heard a lady on a video play the other day, she made the Well-Tempered Klavier (my other "preciousssss) come alive so gorgeously, so full of dance and atmosphere and love... only, being 64, I can't remember her name.
Gracious, I've gone on and on with this kaninschen spur, an issue of metricality rather than the originator's issue of metres per se. Still, the issue is one of the "dare" of risking loss of communication with your audience over a stylistic "anomaly." I have successfully had the choir sing a 5/4 Christmas anthem, but still wrestle with "force of habit" any time we add 2 beats to a measure or try to observe the author's extra 2 beats (requiring the drummer to invent something) which some of the people are used to, but others have cut out for simplicity's sake. Force of habit is a very strong force; it can create shared community, or it can drive people into camps; leaders have to watch what it is doing.
The intellectual superabundance of Bach is undeniable. As a player, I am sure I enjoy it more than my listeners, since I can feel as well as hear the marvels of polyphony and see the journeys of each voice on the page. I love to do artwork while playing a recording of Bach in the background -- Chopin did the same thing. The master of Romantic piano music prepared for his concerts by playing Bach! He said it "gave him ideas."
Since your posts I have been doing some extra thinking on the internal qualities of rhythm -- the rhythm that happens before, on and after the primary beats (not just rubato, but the actual matter of synchronization or non-synchronization, the microseconds about a beat). A few years ago, some jazz players gave me a friendly criticism (I had just joined my first jazz group). They told me I needed to play on "the front part of the beat." A beat is not just a precise moment in time -- it is a Time Thought, and where you place the notes about the beat gives the music meaning (even a digital computer-composed piece has meaning, but a live player gives it more distinction).
Baroque instruments were capable of dynamic range, though typical instruments had less range than their modern counterparts. Keyboard instruments - organ and harpsichord - were incapable of loud and soft, with only the exception of changing stops or keyboards (hence "layered dynamics". This means Baroque keyboardists were in the same boat with comedians - "timing is everything" -- the agogic accent rules.
Last night I listened to a movie (the only one made) of Wanda Landowska playing Bach. In the early 1900's, she championed a return to a more period style and instrumentation of baroque music. There was an easily followable overall beat (as opposed to, say Rubenstein playing Chopin, which is blocks of varying metre flowing in and out of each other like waterfalls and pools); but the themes did not merely "appear" in the time sequence on the page -- they were announced with joy and celebration! I found myself listening more than dancing (which I like to do with Bach), but completely enraptured.
I'm still ruminating on this, but I'm tending to think that the superior player, which is what we want to be, wins your heart with whatever resource he or she uses - relentless beat, rubato or agogic accent. When the player produces a believable music-world, the audience will be glad to enter in.
I think a good song in an odd meter is one that is subtle enough not to jump around waving flags saying "I'm in an odd meter". If people need to learn how to sing it, maybe it is more suitable for a choir than a congregation.
However, have a listen to people singing unaccompanied. My experience has been that it is often hard to clap along in such settings because extra beats get added or, more often, taken away, at the end of each line. Frequently that is a sign that the original relies on the instruments to carry through the gaps at the ends of the line; it also indicates that most people don't carefully count out the beat and will be comfortable with reaching beyond common meters as long as it sounds natural to them.
Do your people clap with the beat?
I'm just having a mellow happy memory of our church introducing contemporary songs, the praise team clapping just like Ron Kenoly on 2 and 4, our Pastor in the front row, having the time of his life, being a good old country boy joyfully swinging his great big arms to clap on 1 and 3 (a scene repeated many times at district conventions, where the cultural waves met from different directions, like the breakers on Oregon's shores). So we ended up clapping on all the beats, which is safe but sort of strange.