I love Glee... But sometimes they make the most bizarre decisions about 1) what songs the characters should sing, and 2) why the characters should sing them. Some of these examples are hilarious. Some are kind of painful. All of them are ridiculous.
In chronological order.
1. "Single Ladies," performed by Beyonce (Season 1, Episode 4: "Preggers")
We see Kurt dancing along to this song at the very beginning... but then it's built into the plot that somehow he's a great kicker on the football team if he does the dance on the field. And THEN it's determined that the entire football team will do the dance on the field to confuse the other team. They do. And they win.
I'm pretty sure this was the episode that determined everyone's stance on the show. If you hated watching a group of guys in full football gear (or whatever the sports term is for that) do the "Single Ladies" dance for no apparent reason, you hated the show. If, however, you found yourself saying, "What? ...I mean, it's awesome. But what?" then you became like me and realized you couldn't ever stop watching.
2. "(You're) Having My Baby," performed by Cory Monteith (Season 1, Episode 10: "Ballad")
Quinn is pregnant, and her boyfriend Finn thinks he's the father (even though he isn't). Nobody knows Quinn's pregnant, and she wants to keep it that way as long as she can... But then Finn is invited to dinner with Quinn and her parents and makes the baffling, hilarious decision to sing this song to her at the dinner table. Nothing like outing your girlfriend's pregnancy in song in front of her religious parents.
3. "Papa Don't Preach," performed by Dianna Agron (Season 1, Episode 11: "Hairography")
Puck and Quinn are babysitting a group of unruly kids. They calm them down by offering to show them "a real live music video." So Quinn sings a one-minute rendition of this song which is, of course, appropriate to her own life but is a ridiculous song to sing to kids you're babysitting. As soon as she's done, they ask for more. Looks like she had time and opportunity to sing the entire song after all. But, hey, maybe she only knew the first verse.
4. "Vogue," performed by Jane Lynch (Season 1, Episode 15: "The Power of Madonna")
Kurt and Mercedes give Sue a makeover by recreating Madonna's "Vogue" video, starring her. It was fun to see Jane Lynch get a chance to sing on the show, but nobody watching this show ever expected to see Sue Sylvester get an entire mildly racy music video all to herself.
5. "U Can't Touch This," performed by Kevin McHale (Season 1, Episode 17: "Bad Reputation")
A bunch of the Glee kids are tired of having goody-goody reputations, so they decide to shake things up. However, they are goody-goody Glee kids. So the only plan they can come up with is going to the library and trying to scare the elderly librarian by launching into this song at top volume and dancing around. It backfires even more hilariously when the librarian loves it and asks if they'd be willing to perform it at her church.
6. "Dream On," performed by Neil Patrick Harris and Matthew Morrison (Season 1, Episode 19: "Dream On")
The fact that they're singing this song isn't ridiculous - it is an audition, after all. However, when they both decide to sing the same song, the guy running the show spontaneously decides there's no time to sing it twice, so they have to sing it as a duet. Given the fact that these two were becoming heated rivals, the time they took deciding who got to sing first had to have taken longer than it would have to just sing the song twice.
7. "Poker Face," performed by Idina Menzel and Lea Michele (Season 1, Episode 20: "Theatricality")
Rachel finds out that her mom is the coach of the rival Glee team. They bond but decide they don't really have a great potential mother/daughter relationship. Maybe that's because both of them think that "Poker Face" is an appropriate duet for the two of them to sing in their fond farewells to each other. Really? Just because they slow it down doesn't make it a heartfelt ballad.
8. "Tell Me Something Good," performed by Matthew Morrison (Season 1, Episode 21: "Funk")
One of the most hilariously bizarre Glee plot points of all time, Will decides he's going to musically seduce Sue, make her fall for him, and then ask her out on a date and stand her up to humiliate her. Even rereading that makes me giggle. The weirdest part? It works. Sue goes crazy and gets all depressed. Now, granted, I'm totally okay with this performance, because it is rather lovely, but it's ridiculous that it happens.
9. The first four songs from Season 2, Episode 2: "Britney/Brittany"
The entire plot of this episode? "Glee kids go to the dentist and have anesthesia hallucinations about Britney Spears songs." The last two songs have basis in reality, but why does the first half of this episode even exist?
10. "Touch-a, Touch-a, Touch-a, Touch Me," performed by Jayma Mays (Season 2, Episode 5: "The Rocky Horror Glee Show")
This episode has a rather idiotic plot as well (a high school production of Rocky Horror? ...HOW?) but the most hilarious is when Sam drops out of the show because he's uncomfortable in his costume, so Will somehow decides it would be completely appropriate for him to jump in and take over the role. Then he asks Emma to help him rehearse this extremely suggestive song. (Note he doesn't sing in it. It's entirely her singing, while she dances around and touches him and acts all seductive and stuff.)
This is a weird scene in and of itself but takes on a whole new level of creepy when you realize that in the show they're planning, Rachel is the one who's going to be singing this to Will. Did he not pay attention to what happened last time he sang a love song with Rachel? And also, how is this even remotely appropriate teacher/student interaction?
11. "Baby" and "Somebody to Love," performed by Chord Overstreet, Mark Salling and Kevin McHale (Season 2, Episode 13: "Comeback")
"We should put Justin Bieber songs on this show. But how? I know! We can have one of the guys suddenly decide to dress up as Justin Bieber, which makes the girls love him, and so then all the guys can dress up as Justin Bieber! BEST IDEA EVER!"
12. "Do You Wanna Touch Me," performed by Gwyneth Paltrow (Season 2, Episode 15, "Sexy")
Aaaaand once more with the appropriate teacher/student interactions. Holly decides that the students need sex ed. She decides that the best way to do this is by singing a pop song about sex to them. Note that this is the group of people who, a year and a half before, performed the very sexual "Push It" by Salt-n-Pepa at a school assembly and, just a month or two ago, performed most of Rocky Horror. If singing and dancing to songs about sex had anything to do with actual sex education, these kids would know all they ever needed by this point in the show.
This second season has been significantly lower on ridiculous plot points, and so there have been fewer ridiculous song performances as well. I'm not sure whether to be happy or sad about that, as the ridiculous choices can be quite entertaining... But as long as the actual performance quality of the songs stays at the level it's been lately, I'm not going to complain about the wonderfully awkward reasons for incorporating those songs into the episode.