"May the angels" is certainly more religious. However the second verse of Danny Boy is of a father asking his son left behind to come and pray over his grave. So for an Irish daddy, it is not exactly inappropriate and speaks right to the heart of those left behind.    We wanted Danny Boy sung for our dad, but had to be content with an electric violin playing "May the angels", which at least gave us the tune.

That said, a few rules are good. Around here we have wills requiring their bereaved to play stuff like George Jones' "He stopped loving her today". It can get really out of hand.