My old High School (not too old, I graduated in 2004) is performing Andrew Lloyd Webber's musical CATS!
Check it out: http://www.lynchburg.org/schools/GlassTheatre/index.htm
Now, to try and verify if they are the first amateur group I did a Google search. I found one high school that claimed to do it back in May of 2005, and they provided some pictures, but I couldn't really confirm it. In addition, the official website says that they rights were released on January 1, 2006. In any case, whether or not they are the first, it's still a great honor for them to have the opportunity to perform it, and I'll definitely go see it (they got the rights to perform Les Miserables in 2003, it was amazing).
I have high hopes, and I hope I'm not disappointed.
