Use a groove made from one of five provided field recordings (courtesy of www.luftrum.com) as the basis for a new track.
Here's what we made:
We used free field recordings from Luftrum:
(Licensed under a Creative Commons Attribution License (CC BY 3.0): you are free to share, copy, remix or otherwise transform the sounds for commercial or non-commercial use on the condition that you give appropriate credit where the sound is used, with a link to me as the author of the sound for example: This [insert track name] contains a free field recording by Luftrum on www.luftrum.com.)
You can also buy a user license of the complete library as pay-what-you-want, then you don’t need to credit me anywhere and all sales go to Save the Children.