A guitar with three necks

I was watching a YouTube video a few minutes ago featuring a performance on a guitar that has three necks. The musician playing the guitar is a man named steve vai. I hate to admit that I have fallen “behind the times” when it comes to recognizing the names of the current names of younger musicians and bands – I guess that is the price you pay when you are working full time, (with overtime) taking college courses at night, and raising kids, too! Anyway, I was surprised to see a guitar with three necks! The musician sure seemed talented! I had to wonder if he ever watched himself on video after he plays – he was making some really funny facial expressions that made me laugh! I wonder if he does that on purpose.