The original music pieces can be downloaded for free from the following places:
And on cases of Spontaneous Winds and Through Bloodshot Eyes the full versions can be downloaded.

Spontaneous Winds:
http://www.newgrounds.com/audio/listen/443090

So Soft:
http://www.newgrounds.com/audio/listen/447209

Through Bloodshot Eyes:
http://www.newgrounds.com/audio/listen/458158
