There's one more thing I wanted to mention about Glee that I forgot, and that's the role of music on the show.
One of the earliest complaints I remember reading about the music is that they didn't use original songs. DUH! Show choirs and glee clubs rarely, if ever, do original music. They take existing music and spin it into their own bit of incredible (or mediocrity). And now that Glee has done original songs I need to know how much people enjoyed them? Personally, with the exception of "Trouty Mouth," which was hilarious, and "My Headband," which was also just a joke, the songs didn't impress me.
The show tends to stick to arrangements of songs we've already heard. Sometimes that's disappointing, the Rocky Horror episode sticks out in my mind, but sometimes it's amazing, like when they did "She's Not There." And, of course, a lot of the mash-ups are great, I posted a link to my favorite, so far, in that other post which is the mash-up of "Don't Stand So Close to Me" and "Young Girl."
Now if Glee were really about a glee club training for shows, we would probably only hear a couple dozen songs rehearsed to death. Fortunately, this is TV and the songs are there to represent how music can underscore our emotions. It's probably safe to assume that nearly everyone has heard a song at just the right time that it seemed to be written about them. Here's a post with several songs that hit me that way and I know I've written about more songs, just don't want to look them up. They're the songs that you used to rewind on the cassette or lifting the arm of the record player for. Today we can just press the reverse button and listen over and over.
My favorite example of using a song to reflect the emotions of a character is "Landslide" from a few episodes ago. Watch Santana's face as she sings all the hurt and confusion and love and a little bit of anger. These are the moments that really make Glee worth watching and this is exactly how music should be used in a show about singing high school students.