There is a particular moment I have seen happen maybe a thousand times now, and it never gets old.
A pub. Late. Somebody starts a song the whole room half-knows. And then there's the part where the singer leans on a line and STOPS, and forty strangers who came in not knowing each other finish it for them. You can feel the temperature of the room change. That's not magic. That's call-and-response, and it is the single most reliable trick in the whole business of getting people to sing who swore blind they "can't sing."
Here is the thing nobody tells you about a singalong. The hard part is never the chorus. The hard part is the FEAR. Yer man in the corner with the pint, the one who's mortified at the very idea of opening his mouth in front of people — he's not refusing to join in because he doesn't like the song. He's refusing because he's afraid he'll be wrong. He doesn't know the words, he doesn't know when to come in, and the cost of getting it wrong in front of strangers feels enormous to him (it isn't, but try telling him that at half nine on a Friday).
Call-and-response kills that fear stone dead. Because there's nothing to get wrong.
You sing the line first. They sing it back. That's it. You've just handed them the words AND the timing in one go. They can't be early, they can't be late, they can't forget the verse, because you do all of that for them and they only have to echo. It's the lowest possible barrier to entry. A child can do it. A drunk man can do it. A Norwegian tourist who's been in the country four hours can do it, and I've watched it happen.
This, by the way, is most of why The Rattlin' Bog does what it does to a room. People think it's the cumulative bit — the piling-up of bog, tree, branch, twig, nest, egg, bird, feather, flea — and don't get me wrong, the FLEA verse is the climax of Western music and I'll fight anyone who says otherwise. But underneath the cumulative structure there's a call-and-response engine humming away. The leader sings "and on that bird there was a feather," the room sings it back, and round it goes. Nobody has to remember the order. The song teaches itself in real time. That's the whole secret. I've gone on about this at length in why cumulative songs work, so I won't repeat myself (much).
But you don't need a cumulative song to get the effect. You just need a song built so the leader feeds and the room answers. And there are gorgeous ones.
The best of the lot, for my money, is The Holy Ground. If you've never led it, here's why it works so well: it has that great roaring "FINE GIRL YOU ARE" that the whole room shouts back, and the "you're the girl that I adore" turnaround, and it's got that rolling momentum where the response is louder than the call every single time. You almost can't kill it once it's going. I've started it in rooms where I genuinely thought nobody was in the mood, and by the second chorus there were people standing up. It's a fishing song, technically, about leaving a girl behind to go to sea, but nobody in the pub is thinking about herring. They're thinking about that one line they get to bellow.
Drunken Sailor is another one — the "what shall we do with the drunken sailor" is a question, and a question DEMANDS an answer, that's just how human brains are wired. You ask a room a question in a melody and they will answer it whether they meant to or not. Same engine. There Was an Old Lady Who Swallowed a Fly works the same way for kids, and for adults who've had enough that they're functionally kids again (no judgment, I'm often one of them).
Now. A few hard-won bits of advice if you want to actually lead one of these and not have it die on its arse.
Sing the call LOUD and CONFIDENT, even if you're not feeling it. The room will only give you back the energy you put in, never more. A timid call gets a timid response, and a timid response means the shy lads stay shy. You have to oversell it. I feel like a complete eejit doing it stone cold sober at the start of a session, and I do it anyway, because it works.
Leave a clear gap. The single most common mistake — bigger than wrong notes, bigger than wrong key — is not leaving enough silence for them to come in. You sing your line and then you SHUT UP and you wait, and the waiting feels like an eternity but it isn't, it's about a second and a half. That gap is the invitation. Fill it and you've answered your own call and now they've nothing to do.
And pick the right song for the right room. A room of total strangers, four pints deep? The Holy Ground every time, or the Bog if there's any momentum at all. A quiet snug with people who actually want to listen? Save the roarers, do something gentler. Read the room. (I have absolutely failed to read the room and launched into a flea verse at a funeral-adjacent gathering. We do not speak of it.)
If you want more of the practical side of all this, I keep a running pile of it over on how to start a session, and the full singable words for the Bog and friends live in the lyrics and the songbook.
The whole point of a folk song was never to be performed AT people. It was to be done WITH them. Call-and-response is just the oldest, kindest, most foolproof way we've found of dragging the shy ones in. Use it. Watch yer man in the corner. He'll sing. They always sing.
Slán go fóill, BogLord2002
P.S. — Rattlin the cat has her own call-and-response going. I say her name, she does not respond, I say it again, she does not respond, and on the third call she walks the OTHER way. Fierce traditional structure on her. Very folk.