All of our music products are delivered as zip files after your purchase. It's recommended to download and uncompress/unzip these files on your computer before transferring them to your mobile device, as many phones don't support the zip format out of the box.
If you want to learn how to uncompress zip files on your computer, please check out: How do I open the zip files that I have downloaded?
In many cases, it's also possible to download apps on your phone that can open and uncompress zip files. Please do a search for "unzip files" or similar in your app store of choice to see what options are available.