One that should be rememered are the verses he wrote in 1972 at the time of the Bloody Sunday massacre in Derry.

On a Wednesday morning early I took the road to Derry
Along Glenshane and Foreglen and the cold woods of Hillhead
A wet wind in the hedges and a dark cloud on the mountain
And flags like black frost mourning that the thirteen men were dead.

The Roe wept at Dungiven and the Foyle cried out to heaven
Burntollet's old wound opened and again the Bogside bled
By Shipkey Gate I shivered and by Lone Moor I enquired
Where I might find the coffins where the thirteen men lay dead.

My heart besieged by anger, my mind a gap of danger ,
I walked among their old haunts, the home ground where they bled,
And in the dirt lay justice like an acorn in the winter
Till its oak would sprout in Derry where the thirteen men lay dead.

Seamus sent it to Luke Kelly, and suggested the tune "The Boys of Mullaughawn", but Luke thought the tune was too slow, and never used it.

Twenty years later it came to light when Seamus sent it to the paper, and it was printed in the Guardian.

I put a tune to it, and I added a verse - well the original had a fourth verse Seamus didn't send to the paper, for reasons of his own. I don't imagine my verse was anything like his, but I wanted to take into account the time that had passed - and I echoed the line he put in a poem as a verdict of politics in the North "Whatever you say, say nothing."

Once more I went to Derry where so many now are buried
When all is said and done but still there's nothing to be said
And the blood runs in the Fountain and the numbers still are mounting
And there's dead beyond all counting since the thirteen men lay dead.

And I ended repeating the first verse, but with the last line changed to

And flags like black frost hanging forthe thirteen men laid dead

A bit cheeky changing and adding to the words of a Nobel laureate - but later Frank Harte said he sang it to Seamus and that he was quite pleased at his words getting sung, and he didn't mind the extra verse.