I'm gonna be honest: I couldn't finish this one.
So, like, Elvis was famous, but was he really famous for singing fantastic songs? No. No way. He was famous for singing songs and being "1950s sexy." I don't mind a few of these songs, but again, I'll be honest with you: if I want to hear an Elvis song, I'll listen to the Elvis recording of that song. They don't hold up very well outside of Elvis and they definitely don't HELP to make a super confusing adaptation of Twelfth Night any better.
But, let's talk about Twelfth Night for a minute. The actual play, the one by Shakespeare. It's great, right? One of his very best. I can see why someone would be like, "ok, GREAT IDEA, everyone: let's take one of the best plays ever written and the musical catalog of one of the most famous musicians ever and COMBINE THEM!"
I hate the audience who not only puts up with that line of thinking, but gets excited about it.
The funny thing about All Shook Up is that I saw a staged reading of an early version show in 2003 and it was much better. It was still all Elvis music, but the story was way better. AND it was starring Ana Gastyer, who was in-cred-i-ble. I wish I could remember more of the story of this version. I don't remember LOVING it, but I don't think it was the worst thing ever, which is kind of how I felt about the current version.