Come on you Welsh, show a bit of imagination! Do what the Liverpool kopites did, take the song by the scruff and change the words! Here's The Fields of Athenry, as sung on the Kop:

Outside the Shankly Gates
I heard a Kopite calling:
Shankly they have taken you away
But you left a great eleven
Before you went to heaven
Now it's glory round the Fields of Anfield Road.
All round the Fields of Anfield Road
Where once we watched the King Kenny play (and he could play)
Stevie Heighway on the wing
We had dreams and songs to sing Of the glory round the Fields of Anfield Road
Outside the Paisley Gates
I heard a Kopite calling
Paisley they have taken you away.
You led the great 11
Back in Rome in 77
And the redmen they are still playing the same way
All round the Fields of Anfield Road
Where once we watched the King Kenny play (and he could play)
Stevie Heighway on the wing
We had dreams and songs to sing
Of the glory round the Fields of Anfield Road.
Outside the Hillsborough flames
I heard Kopite mourning
What so many taken on that day
Justice has never been done
But theirs memory will carry on
And it's the glory round the Fields of Anfield Road.
All round the Fields of Anfield Road
Where once we watched the King Kenny play (and he could play)
Stevie Heighway on the wing
We had dreams and songs to sing
Of the glory round the Fields of Anfield Road.
Of the glory round the Fields of Anfield Road.

I think we call it the folk process...

You can even hear it, given a quick google! :-)