SimpleSounds is a fast growing YouTube channel, they upload 3/4 times a week. All music they place is from other YouTube channels. You can download the music in different ways. You can download all the music for free, and it is all non-copyrighted.
How to download
Go to the channel.
Choose a song and copy the video URL.
Go to www.youtube-mp3.org
Place the link in the bar.
Click convert and download the song.