I built a symphony a few days ago. Some parts may be messed up.
The roof is slightly messed up because I kinda rushed it. I may update it to make the roof a half dome of glass.
Texture pack used is Dokucraft-High

Inside the symphony are colors of wool. They represent the instruments. Key is below
Lime Wool-Bass Guitar
Orange Wool-Bass Drum
Purple Wool-Piano
Cyan Wool-Clicks/Sticks
Red Wool-Snare Drum

Structure inspired from the San Francisco Symphony (you can see some similarities)

Things to Help Me
Singleplayer Commands
TooManyItems
Creative Mode
Worldedit