More importantly, a high school talent show in 2013 isn’t going to be won by covering a lengthy 70’s or 80’s prog-rock song. 
True, true. But I don’t think they’re going to challenge themselves that much. It’s just a talent show. The band playing tight is more important.
+1 You gotta remember, this isn’t an audience of musicians. You need to play something sort of challenging so you can have fun, but it needs to be something that the audience can appreciate. Not everybody can appreciate, say, the technical masterpieces Dream Theater or Porcupine Tree can make
this is a talent show, where you show your talent. you can’t do that by playing popular stuff like jason mraz or fall out boy. If you’re going to play rock like that, then by all means you should challenge yourself.
If you want some rock or Indie song, I suggest Imagine Dragons or Two Door Cinema Club. I have tons of more suggestions in my head if you don’t like them
Not bad rhetoric for a young man! My response, however, would be “it’s a show.” Moreover, we know that the purpose of a talent show isn’t to prove the highest degree of talent, but to show your talent with the highest degree of showmanship.
Or in other words, you have to win the crowd to win the show.
Never saw anyone win a talent show by sitting down and composing a piece of music on a sheet of paper in realtime. Or work through a differential equation on a projector screen! The person playing Jason Mraz will beat them every time, with less talent.
Maybe “Carry on My Wayward Son?” Tons of people know it and it’s fun to play.
If you do want to go with a very challenging song, at least make sure it’s one of the more popular songs. Songs like “The Spirit of Radio,” “Tom Sawyer,” “Comfortably Numb,” and “Money” are more likely to be known by the masses.
That would be super cool, Im sure the audience would enjoy it
I know that these aren’t really high energy like you wanted, but I see them working in a talent show if you pull them off well.
These just came off the top of my head.
For 100 bucks i can send you my original song… :