I took a MIDI class in the fall and we used logic on macs with an M-audio keyboard. The keyboard was hooked up to an audio interface who's only purpose was to plug our headphones into. I'm looking at the m-audio keyboards and they all have built in midi interfaces so all you need to do is connect it via USB. My question is when I get my MacBook pro, hook up the keyboard with USB, will I need the same thing we used in class to get sound? Or can I just plug my headphones into the headphone jack on the MacBook pro and I'm good to go? If this works, will hooking up some high quality headphones by using a 1/4 inch to mini jack adapter lower the quality all? Thanks!