Arduino Controlled Skeleton Rock Band - a work in progress

Hello everyone. I'm brand new to Arduino and I'm loving it so far. I got into it because I love Halloween and making my own props and displays. This year I wanted a Skeleton Rock Band as my main feature. I started with scraps I have lying around and I'm building on to it as time goes by. I posted an instructable with many of the steps I used to create this setup. You can see it at http://www.instructables.com/id/Animatronic-Skeleton-Rock-Band-in-Progress/.
There is also a video on youtube with the setup as it stands now - Boo Frighters - Halloween 2016 - Grave Grohl & Impaler Hawkins - YouTube.

I'm still adding on to it and changing things around, but I love how I can control just about everything I need to.

I'd like to add more audio files and have them play randomly when triggered, but I have time to figure that all out.

If anyone has any input or suggestions for cleaning things up a bit, I'm open to ideas.