We are happy to welcome guest celebrity blogger Hunter Foster, who was Tony-nominated for his performance in Little Shop of Horrors. Foster, who is currently playing Sam Phillips in the new musical Million Dollar Quartet, will blog for Playbill.com all week; his third entry follows:

My failed attempt to awake to "Turkey Lurkey" continues. My alarm clock just doesn't want to play the song. But, I did wake up to an interesting thought: what constitutes a musical? Yes. Sometimes those things just pop into my head at 9 AM along with how many glasses of wine did I really drink last night?

It is truly one of the strangest seasons I've ever seen. There are only two — let me repeat that — TWO musicals that have an original score: Addams Family and Memphis. The rest of the musicals — including my own, Million Dollar Quartet — use pre-existing material. And some musicals, including American Idiot and Come Fly Away, also have little if any spoken dialogue. I haven't seen Sherie Rene Scott's Everyday Rapture but from what I hear, despite the fact that it's blissfully well written and she's giving a dynamite performance, the show has more in common with Elaine Stritch's wonderful At Liberty than Oklahoma! And with the opening of Enron last night, with its theatrical use of song and dance to tell the story of the collapse of the Texas business giant, many people wonder if it's more of an original musical than the revue Sondheim on Sondheim.

So, I ask the question, if this trend continues, should there be certain guidelines to define what a musical is? Or is it better just to keep the lines blurred between art forms? Or is the entire art form starting to morph into something else? I mean, if the Tonys were to nominate Come Fly Away, American Idiot, Million Dollar Quartet and Sondheim on Sondheim, there would be no original scores in the Best Musical category. In fact, Million Dollar Quartet would be the only one of the four that most would consider to have a traditional "book." And MDQ is far from being a traditional musical.

I guess, as the clock switched over to 9:05 AM, I came to the conclusion that anytime people are experiencing something theatrically fulfilling, whether it's the music of Green Day, Elvis, Sinatra or Lippa; the performances of Nathan, Bebe, Babs Cook or Levi; the stage craft of Twyla, Mayer, Ashley or Schaeffer — then it's all theatre. Whether you want to call it a musical or not, it's all theatrical.

And in the theatre, that's where magic can happen...

And on that note, I have to go do a matinee!