I will send a demo in AIFF. form to a studio and they will send me back a mastering of my song in WAV. form. My question is can I burn a CD with a Imac with Moutain Lion trough Logic Pro 9 ? or which way will I be able to listen to it. Thank you,

Is the CD for the mastering house? If so, yes you can burn a CD with your iMac. Do you have a CD Burning application like Toast. If not create a burn folder on the Desktop (on the Finder go to File > New Burn Folder). Now drag your AIFF file to this burn folder. Click on Burn and this will burn the file to a CD. If you want to create an Audio CD that can be played back in a CD player, you will need an application like Toast to do this, where you have the option to create an Audio CD.

No they will send me a WAV. file. But the info is very helpfull. Thank you again