"Don't Go Breaking My Heart". C. Totally vanilla, but it was supposed to be. It makes perfect sense that Finn and Rachel would believe their saccharine (and obvious version) of the Elton John classic to be the most adorable thing ever, whereas the rest of us (and the rest of the characters in the glee club) would have a reaction that was closer to a dry retch. Their mediocrity makes you take notice of now much more interesting the other performances were, which is great, because far too many episodes of "Glee" have involved Rachel and Finn getting the keynote performance that the whole episode revolves around.
"River Deep Mountain High". B+. Great energy, great singing, and I'm a sucker for Spector (although this has never been high on my list of Spector favourites).
"Le Jazz Hot". A-. I can't remember a "Glee" episode that did a better job of letting the actors play to their strengths. Let's see ... we've got a cast full of musical theatre veterans who specialize in singing jazz standards and show tunes ... hey, let's turn them loose on jazz standards and show tunes! Probably Chris Colfer's best performance ever on this show.
"Sing". B+. As far as flawed performances go, this one is as good as you'll likely ever see on "Glee". Here you've got two characters (and actors) who are really good dancers but aren't strong singers. So they picked a song that they could get over on the strength of their dancing, facial expressions, and comedic timing (which is more of a dance skill that a singing skill). And since the song is about a guy who can't really sing, the song title (and lyrics) actually tie into the show's plot. This one performance did more to develop the characters of Mike and Tina than the last several episodes put together.
"With You I'm Born Again". B. The performance itself is terrible, maybe a D+. But as a performance that was supposed to be terrible, it was a winner. The costumes, the double meaning of "born again", the fact that it was a perfectly believable performance by Finn and Rachel (you can really imagine those characters thinking they'd hit upon a real winner), all of it was brilliantly executed. The grade would have been higher if they'd gone even more OTT with it.
"Lucky". C+. Cutesy to the point of near unwatchability, but again, that was the whole point. Obviously this by-the-numbers Jason Mraz cover (it seems as if Sam isn't capable of doing much else) didn't have a legit chance of winning the competition on its own merits, but again, it won believably. Any glee club member could reasonably think that some of the others were taken in by its simplicity and charm, and in that sense it was good enough to win, but not bad enough to make anyone suspect that its win was the result of shenanigans.
Artie and Brittany's "breakup" scene. F. I honestly laughed during this scene, I thought that one of them was putting the other on until the scene suddenly ended. Are we supposed to believe that three brain-celled Brittany has suddenly developed a conscience? Are we supposed to feel sorry for Artie and his dropped-like-a-bomb-out-of-the-clear-blue-sky angst over the workings of his dong? This was easily the worst scene in an episode with almost no weak scenes.
"Happy Days are Here Again/"Get Happy". B+. See earlier comment about allowing stage veterans to sing to their strengths. Bravo!