Jay Prichett is actually a good singer?

In S2E16, Jay sings Danny Boy and the last line of the episode has Manny saying, "Keep this up, and this won't be the last plug i pull." While the line is hilarious, I felt that Jay is a soulful singer. Is that part of the joke, and I dont get it? Or am I the only one who finds his song lovely and would like to hear more?