How do these soccer chants evolve and propagate?

On Welcome to Wrexham (non-fiction), the fans sing a little ditty about their guy, Paul Mullin:

"We’ve got Mullin, Super Paul Mullin,
I don’t quite think you understand.
He plays in red and white,
He’s f*cking dynamite,
We’ve got super Paul Mullin!

And on Ted Lasso (fiction), they have their song about Roy Kent:

“Roy Kent, Roy Kent. He’s here. He’s there. He’s every-fucking-where!”

How do these songs propagate amongst the fans? Like, does a local band write it, it gets some radio airplay, the fans pick up on it, then sing it at the match? Does some fan come up with it, sing it with his mates, and hope the other fans pick up on it?

My guess would be that they start with school or other low-level teams, where the crowd is small enough for it to easily spread to everyone. Then, at some point, a bunch of folks from that school go to a larger event and sit together, and re-use the chant (obviously with the name changed), and there are enough of them that it can be heard by others and spreads further.

Most soccer teams have so-called capos.
“Perched at the head of large swaths of their club’s most ardent fans, they serve as pseudo-orchestra directors , actively conducting their fellow supporters in organized song, chants and visual support.”

https://www.mlssoccer.com/news/life-capo-they-may-not-always-watch-game-they-always-affect-it#:~:text=Perched%20at%20the%20head%20of,but%20they%20always%20affect%20it.

In the case of the Wrexam team, I’d have to go back and find the episode, but I do believe that yes, a local band wrote the song and that chant is the chorus.

To me it’s sort of like when crowds at sports events in the US start singing “We Are The Champions”

I’m waiting for people to start singing “Bring on Deadpool and Rob McElhenney” in those clips they play showing fans walking into the STōK Cae Ras

In Germany at least, no one has to write new songs, but the fans take existing tunes from all sources, pop or rock songs, schlager or even arias or other classical tunes, and write new football specific lyrics to it. Some of these chants have strongy staying power, the following two examples have been sung in German stadiums for almost 50 years:

Zieht den Bayern die Lederhosen aus
Lederhosen aus
Lederhosen aus

(to the tune of “Yellow Submarine”)

Ihr seid Schalker
Asoziale Schalker
Ihr schlaft unter Brücken
Oder in der Bahnhofsmission

(to the tune of Bonny Tyler’s “It’s A Heartache”)

I Indianapolis, we have a minor league soccer team, the Indy Eleven. I had season tickets for the inaugural season 11 years ago - and we arrived, the unofficial booster club (the Brickyard Battaion) had written out a dozen or so chants and songs, printed them out, and distributed them at games. They sit in one of the ends, and have a makeshift band of sorts, and they lead the crowd through whatever chant/song is appropriate at the moment

I’m sure as players are added to the team a new chant organically develops from that crowd.

There are now several chants about individual Wrexham players. Unfortunately the excellent ‘Welcome to Wrexham’ documentary doesn’t say who composed them…

So big part of it is the away fans. A section of the ground for each game is designated the “away end” where tickets are assigned to the supporters of the opposing team (traditionally this was because it was not considered safe for the opposing supporters to mix with the home fans). The travelling community of fans for a particular team that supports that team in the away end wherever they travel tends to be close knit and has long bus journeys to come up with amusing songs

I found these for your entertainment:

We’ve got Mullin,
Super Paul Mullin,
Just don’t think you understand.
He plays in red and white.
He’s fckng dynamite,
We’ve got super Paul Mullin.

“We’ve got Mullin” The fans react to Mullin’s return from injury. (youtube.com)

Less than a mile from the centre of town,
A famous old stadium crumbling down,
No-one’s invested as much as a penny,
Bring on the Deadpool and Rob McElhenny!

ALWAYS SUNNY IN WREXHAM -DECLAN SWANS (youtube.com)

Ryan and Rob like to play jokes on each other - here’s Ryan in action (N.B. Paul Rudd is in the video on the left.)

RYAN REYNOLDS sings it’s MCELHENNEY Before WREXHAM FC vs Boreham Wood (youtube.com)

I’m reminded of a meme I saw awhile ago that went like this;

American sports fans: DE-FENSE! (stomp stomp) DE-FENSE! (stomp stomp)

European sports fans: Alright lads, I’ve worked up a little ditty about the other team’s forward’s drink driving arrest set to the tune of Debussy’s Claire de Lune, I’ll count us in

I remember Arsenal fans celebrating being in the lead in a European away game in France, most of whom had probably drunk a few too many beers. The Pet Shops Boys “Go West” came on the sound system and they started signing along in joy and it was completely natural to replace the lyrics “go west, it is peaceful there” with “1-0 to the Arsenal”. I know that’s a much simpler song but that tune was added to the jukebox of all football teams at that moment. That was in 1995, and the fans still sing it today.

Most chants use familiar tunes and are adapted for context. A handful of hardcore fans sing a new chant, usually during an away game when the loudest and drunkest fans are positioned close to each other, and the fans around them soon pick it up. Then in the next home game it spreads to those fans as well.

That Wrexham chant is to a familiar tune used by football fans up and down the UK, with similar terms. It’s not hard to pick up if you’re a Wrexham fan hearing it for the first time and it’s super fun to chant with the rest of the fans in the stadium, plus it creates a great atmosphere to be in. And it helps your team.

I’ve started a few already well known chants, and it is a great feeling. But I’ve never invented a new one.

My favorite one: “Luis Suarez, your teeth are offside”

See also: “Mesut Ozil, your eyes are offside

In 1996 Premier League Newcastle United, seeking their first title since 1927, finished second to ManU after leading the league by 12 points.

To the tune of Daydream Believer

Same here in Argentina, for example the immortal hymn “Jugadores” (Players), set to the tune of Bonnie Tyle’s “It’s a heartache”:

Jugadores
(Players)
la concha de su madre
(The c**t of your mothers)
a ver si ponen huevos
(mmm, let’s go with “show some courage” (literally is “let’s see you put some eggs”))
que no juegan con nadie
(That you are playing nobodies)

Usually directed by the fans towards their own players when they feel they are underperforming against weaker opposition.