17 is still incredibly young to write a song like that one. I wasn't quite sure what the sge was and didn't have time to look it up.
I sort of recall seeing a bit on RTE ot tg4 about him but can't remember if it wad part of something else, a dedicated doc on him or perhaps an episode of Aistear an Amhráin about the song or yet something else.
I do rememberan interview with the man behind the bar in John B's telling how MM came into the bar, sat down and wrote aldilidlyaldi in something like fifteen minutes, so perhaps there was a documentary or wlse I am conflating several things I have seen in the past.