I agree with thefanof, this episode nearly jumped the shark. (compared to Season 1 and the best episodes of this season)
Mel actually was the source of most of the "last ditch attempt" filler laughter (she, out of the cast, was the best when it comes to this episode). Bret and Jemaine's strong point was ONLY the first "Scarborough Fair" tribute, not knowing the lyrics.
The excelling song in this episode was "Demon Woman". And the one that nearly jumped the shark was... well... *silence*
You can argue that all FOTC filler material is genius. Last episode was a prime example. This had a few, but not as many really humorous moments as before. I'm gonna quote thefanof, because it is the most appropriate way to sum this episode up:
"This is not the FOTC we have come to expect."