TSO started as a side project for the members of Savatage, a metal band that has been around since the early 80's. Its the brainchild of Jon Oliva, the original Savatage lead singer. TSO has grown into a MAJOR production over the last few years. It slpits into 2 touring companies (one for the Western states, one for the Eastern), and features current and former members of Savatage singing, playing guitar, etc, along with a full orchestra (even guys like Alex Skolnick, ex-Savatage and ex-Testament guitarist).
I had tickets 3 years ago, but my grandma died 2 days before and I had to scrap my plans. Still trying to catch them in concert. Not everyone's cup of tea, but I personally really like them. Their version of "Carol of the Bells" is just incredible.