[Blade]

It would be hard to tell someone what to sing having not ever heard them sing. My advice would be to sing something that you are very familiar with, yet a song they may not be familiar with,ex...a song that wasnt cut as a single off of a CD, a song that shows the depth of your range and a song that you can dub with your own adlibs....the first examples that come to mind on this are Elvis' live in concert version of "How Great Thou Art" or both Diana Ross and Lionel Richie's parts in Endless Love. Great range expression and they threw in a lot of extra vocal adlibing in both of these songs.

As someone else said don't sing a song made popular by one of the judges and try to get the audience going. You want to capture your audience, like I hope this never ends, not make them feel captured, like when is this going to end.