Free Music Software

Sonic-Pi - Live music coding program.  http://sonic-pi.net/

Audacity - A free sound recorder and multi-tracker. It is very useful. http://audacityteam.org/

Reaper - It is a free trail for 60 day but it is highly effective as a Digital Audio Workstation, but only $60 dollars for the unlimited version. 

Tracktion 4 - Completely free for Windows and Mac. A simple signup and download.

https://www.tracktion.com/account/signup/index?step=3a&