Writing poetry and writing song lyrics are equal but different artforms. It's all about phrasing. If you write poetry with a metre suitable for singing you're wasting the medium of poetry. The whole point of the spoken word, against the sung word, is that even when written in strict time it creates a subtle cadence of its own, which can only be spoiled by the addition of a tune.

The repetition of 'known' referred to above is a perfect example - in the poem the return to that 'key note' adds power - but when you sing it you can't return to the note there, so it just sounds like bad writing. And that lovely 'stint/tint' line becomes gobbledgook. Read the original poem aloud - you'll soon see what I mean.

Likewise song lyrics, spoken, tend to sound pedestrian - no matter how beautiful or clever the language.

Great songwriters understand how to match lyric and melody so that they add their own harmony to eachother - something horribly missing in Raglan Road which works fantastically in some places (purely by luck) but which is an embarrassing joke in others.

If Kelly was so smitten with Lavanagh's poem he should, with the poet's permission, have witten new words (with full attribution, of course), that DID work with the tune, and did convey Kavanagh's images and idea adequately through the very different medium of song. Or if that was impossible or beyond his skill, he shouldn't have bothered.

Bodging one to the other was lazy and disrespectful to both works, and produced a mess - which is why everyone sings it wrong.

They have to.