Lou Gottlieb, he of the Limeliters, loved this song and gave me his interpretation of it one day. Lou said it is a father or a grandfather singing to his son/grandson as the young man goes off to war. He interpreted the lyrics line by line:
"Oh Danny Boy" - Who would call another man "boy" Lou asked. Only a father or grandson.
"The pipes the pipes are calling" - That's the pipes of war.
"From glen to glen and down the mountain side" - When the English wanted the Irish lads to fight their wars, they would send pipers to the hills surrounding the towns where they would pipe the pipes of war.
"The summer's gone and all the roses falling, it's you it's you must go and I must bide" - It's too late in the father's life for him to fight; it's the son who must go and fight.
"But come you back when summer's in the meadow, or when the valley's hushed and white with snow" - no matter when the son comes back, in summer or winter ...
"It's I'll be there in sunshine or in shadow…" - I'll be waiting for you whether I'm dead or alive.
"Oh Danny boy, oh Danny boy, I love you so." - That line is self evident.