OpenGameArt.org
Decisions
Credit line
"Decisions" by FrancisLeeMusic licensed CC-BY 3.0: https://opengameart.org/content/decisions-1 Author's attribution notice: Head to http://francislee.squarespace.com/services for attribution guidelines.
Where to put it: Game credits or video description. If the entry has a "Copyright/Attribution Notice", follow that.