What is the Creative Commons Non-Commercial 4.0 License? 

For an overview, as well as the full details of the license, please visit https://creativecommons.org/licenses/by-nc/4.0/

It is your legal responsibility to use and attribute the music in accordance with the license.

I understand the CC BY-NC 4.0 License and my use qualifies. How do I properly attribute? 

Awesome! Attribution should be formatted as:

"Song Title"
Cactus Slim Records
CactusSlimRecords.com
CC BY-NC 4.0

I purchased a license, am I still required to post attribution? 

Nope! Although it's always appreciated!