How do I set my MPC 1000 to have each midi channel set up to play different sounds? Right now once I change the midi channel from "1a" to "2a" to "3a" and so on and on... it changes the sound that I use from "1a." Quick example... when I choose to use a string for my first track, "1a" midi destination, then once I am ready to move to "2a" on track 2 and choose another sound like a brass, then track 1, "1a" plays the brass instead of the string that I recorded in it. I want to be able to play the string and the brass, and any other sound I use from 1a-16a if I use that many sounds. Can someone please help me out?