There are several elements that you will need if you are going to get serious about creating music on a Mac. The hardware simply boils down to a digital audio interface, MIDI interface, keyboard and of course your computer. Once this has been installed you will need to choose the right software to control it all.

MIDI Keyboard

MIDI and audio routing is built into Mac OSX, at the system level.
A sequencing application such as Apple Logic Audio, or Steinberg Cubase SX, is also essential if you are going to be requiring professional hardware support for your new equipment, this will allow you to layer multiple audio and MIDI tracks, and control several devices at onceLogic

We supply basic keyboards, Midi interfaces (both USB and firewire), Microphones and Software Applications like Reason, Cubase, Ableton Live, Traktor