It's a great song by Gerry O'Beirne. I believe the song is partly inspired by the life and untimely death of Micho Russell, an Irish piper from County Clare.
I don't know if Gerry ever checks in here, but if you're there Gerry, feel free to chime in.
As to how "shades of Gloria" fits in with Micho's renowned piping and contribution to preserving traditional Irish music, I can't say exactly for sure. If you visit Micho's hometown of Doolin, and have a look around at the sea and the cliffs, it is certainly glorious.
There's a very informative Wikipedia page on Micho at:
http://en.wikipedia.org/wiki/Micho_Russell
and Gerry O'Beirne can be found at
http://www.gerryobeirne.com/