Audio Hijack is a great app for Mac users that allows you to capture and record audio from all over your Mac.
With a recent update, Rogue Amoeba (publishers of Audio Hijack) added the ability to live stream your audio out to the internet to platforms like Periscope, YouTube Live, Twitch, and many others.
I recorded this tutorial showing how easy it is to now live stream right from Audio Hijack out to the world.