So, I have like 5 different mouthpieces and I was wondering if you are supposed to use different mouthpieces for certain types of music.

Find one or two that you`re most comfortable with and that gives you the greatest range, and sell the rest of them. I sometimes use a 10 1/2C with a large backbore for jazz, and a 7C for everything else.

it depends... how long have you been playing... and what are the sizes... and what kind of music do you play? answer those and i should be able to give a good answer