Thank you for trying Cakewalk In Concert's Demo version! The Easy Install option will install everything you need to begin, including the In Concert Demo application, documentation and music, and MidiShare 1.68, MIDI connectivity software that allows you to connect your MIDI keyboard to your Macintosh.
If you already use another type of MIDI connectivity software, like the Open Music System (OMS), select Custom Install from the menu above and choose an install option that does not include MidiShare.