So it's gone through several transformations. I've had this truck maybe 15 years. Things are constantly changing, and as I change stuff around, different instruments don't fit where they need to fit. The biggest thing is space. The hardest part is balance.
Different instruments are louder than other instruments.
Everything is acoustic, nothing is amplified, so that means that the trumpet has to be softer than the guitar. This piano has two inches of foam rubber under it and there's felt between every other string. There's a constant state of design, with different mutes for the different horns, so it's a constant battle. That, and keeping everything in tune with itself. If you just play one instrument, then you're playing that all the time and constantly keeping it in tune.