Magical! See John Williams conduct Harry Potter music at Hogwarts castle

You don't just cut a ribbon to celebrate Harry Potter. The Wizarding World of Harry Potter in Universal Studios Hollywood marked its grand opening Tuesday night with one of the most magical things we've ever seen.

First, in front of Hogwarts Castle, there was a choir of students and frogs.

And then, it happened: We got a Harry Potter concert, courtesy of John Williams, himself.

Williams conducted the L.A. Philharmonic while a light show projected on the castle and fireworks lit up the sky.

We hope Ollivanders sells Williams' wand! The park opens to the public on Thursday.