Omar Lopez is in the process of writing his thesis on how to create music through artificial intelligence. While working on this ground breaking task, he is giving away many of what his AI created for free. Currently his dataset has half a million midi files which he is turning into MP3's for people to listen to or use in their projects. You can use any of the MP3's he created at the bottom of this page.
So how exactly were these made? Omar explains "I use data analysis and then a bit stochastic (random) process to produce them it comes out as a rendered midi file with a workstation with virtual instruments that transform those into signal signal (mp3)."
The way Artificial Intelligence works is complex. In a nutshell, an algorithmic program listens to samples of real music, then outputs a new take on it.
The good news is that the files below are completely free for use under Creative Commons. If you want to know exactly what this entails, Omar cited YouTubes terms of service as one he wanted to go with which you can learn about here: https://support.google.com/youtube/answer/2797468?hl=en
Omars Sound Cloud account: https://soundcloud.com/omar-corner
Omars YouTube channel: https://www.youtube.com/channel/UC86mklhno7NZFWA1GW5gnKA/
MP3's (Right click to save)