Christy's book sheds no light on this I'm afraid. He credits the entire song to Bobby Sands MP, which must be questionable, unless of course Gordon Lightfoot took the air from Bobby Sands' song, which I don't believe is the case.

Christy Moore first heard the song in Derry, sung by someone who had been released from the H Blocks. It was attributed to a song-writer called Marcella, who Christy says he later found out was actually Bobby Sands. He makes no reference to finding an air for the song, so I assume this means that the song came to him complete with the air.