music composition

Hello people! I'm planning to compose and produce electronic music on the mac and I'm looking for some great and (hopefully) easy to use software. I'm not planning to record live instruments, only use ready made samples. I got a midi keyboard which I'd like to use as well. What software would...

I'm not sure where is the best place to post this question, but I figured Apple fans + audio people may be my best bet. Does anyone know the name of the song in this video? It's the latest introductory video for the MacBook Air: It sounds like Apple or the production company may have created...