Recently me and my girlfriend have been making some music on our macs since we got them. Someone we know has asked us to play some shows with them, and I have some simple beats and stuff on my MacBook, and was wondering how I'd use the MacBook in a live setup to act as the drum machine? I pretty much have no idea where to start/what to buy to accomplish this. If anyone would be so kind to explain or just post a link to somewhere where I can read up on it, it would be much appreciated.