Harmony does something to my brain than I can't explain but it's like a short cut to, well, I dunno, but something good.

I'd really like your suggestions for harmonies that create emotional response.

Sorry for dumping a huge number of links here. Here are two favourites:

Picforth, In Nomine a 5.

and

Cork Sacred Harp - "47b Idumea"

Here are some examples: (and now that I post them, I realise some of them aren't really harmony proper, so I'm not sure what I'm asking for)

Irish lilting in harmony

Beloe Zlato - "За тихой рекою" (beyond the calm river?), and a better but more noisy version Белое злато - "За тихой рекой" (Белое злато / Beloe Zlato / White Gold -- I don't know anything about this group and if I'm posting Russian propaganda please let me know because I don't want to be doing that)

Mamas and Papas - "California dreaming", "Here in my arms" (although Ella Fitzgerald's version is much much better), "Safe in my garden" (especially the bit around 1:50 building to 2:15)

Sacred Harp choirs. Sacred harp and "shaped singing" is how you teach people to sing if they can't read music. [https://en.wikipedia.org/wiki/Shape_note](Wikipedia has a good explainer). They start with a verse of the soh, lah, ti, fah sounds so people know the tune and rhythm and then they launch into it. I'm not religious (in a quiet, polite, respecting other people's religions kind of way) but they turn out a great tune sometimes. Henderson, Texas - Sacred Harp 463: "Angel Band", Austin, Texas - Sacred Harp 463: "Angel Band", Unknown - scacred harp 463: "Angel band". Camp Doremi Europe 2015 - Sacred Harp 117 "Angel Band". I've dumped four of the same song so you get a feel for differences in pace, in size of congregation, and skill of singers. The acoustics of these rooms suck, and even skilled professional sound engineers are going to struggle to mic up these rooms and get good output, but I like the fact that every consumer grade mic and recording equipment is just OVERLOADED TO ALL HECK.

More sacred harp. Texas - Sacred Harp 505 "Cleansing Fountain". The lyrics are really something.

Irish sacred harp, and this is the one I really want to share because my word they mean it: Second Ireland Sacred Harp Convention - "47b Idumea" there's a woman really singing. I love love love this. There's also Cork Sacred Harp - "Come thou fount"

It's not just vocal harmony either. Lankum, NPR Tiny Desk Concert, "The Wild Rover" just builds and builds layer upon layer. (And "Bear Creek" does something similar, with more joy. The Mary Wallopers - "Frost is all over" have something going on underneath this romping joyful noise and I think it's the sneaky "Banish Misfortune", so here's a version of that Sorcha Ni Scolai - "Banish Misfortune" and it's all amazing but there's a tiny bit at 1:19-1:25 that gets right into my brain.

Sometimes it's just a big crowd. From a comment by @jgb I found this Welsh National Anthem just before Wales beat England. Here's a Welsh flash mob Cor Meibion Male Voice Choir - "Bread of Heaven"

And I think it's not just "harmony" proper that I'm thinking of. A bit of nice tune in the middle of near chaotic noise is nice. So, for an example, listen to all of this The Incredible String Band - "The Mad Hatter's Song" and stick with it, because at 3:40 they suddenly drop into this very short, but very sweet bit of nice tune. And that "I am the archer, the lover of laughter, and mine is the arrowed flight; I am the archer and my eyes yearn after the unsullied sight" is lovely.

I'm listening to a bunch of music from the 1500s, and especially In Nomine. The strings sliding all over the place is amazing to me. In Nomine À 5, "Seldome Sene" · Christopher Tye · Jordi Savall, In Nomine À 5, "Rachells Weepinge" · Christopher Tye · Jordi Savall, In Nomine IV A 6 (Strogers) · Hespèrion XX · Jordi Savall, Youtube have given this weird artwork Picforth, In Nomine a 5.