Apparently the Catholic Church in Ireland has a document prohibiting secular poems, songs, tributes, etc. during the actual funeral Mass.
On the surface, it seems a bit draconian, but I guess you could say that they could do those at the wake, or whatever.
"(J)azz musician Paddy Cole revealed...that he was not allowed to play at his mother's funeral Mass. "Folks, a tiny bit of rule-bending in this matter won't hurt anyone nearly as much as being sticklers undoubtedly hurt him. Just saying.