What companies customize band instruments?

It depends on what kind of band. If it's a rock band then i would be every instrument besides drums, bass guitars, guitars, keyboard, and sometimes violins. If it's a school band then it woudl be any...

bass, electric, vocals, drums, keyboards(maybe)

Typically a guitar or 2 a bass guitar a drum set and a mic

the oboe is used in about all categories of of musical groups...even in marching bands. and yes, oboes are in the orchestra, and band as well.

Pianos.