Multiple Audio Output

I was wondering if there was a way to play audio (from iTunes) through the audio jack and bluetooth from my MacBook Pro. There are two "towers" that I will be using, one will be right next to my Macbook using the audio jack from the computer, and the other will be a bluetooth connection. I haven't been able to figure out how to get both to play music at the same time. Any help or input would be greatly appreciated. Thank you.