All downloadable merchandise purchased from Tapspace is delivered in zip archives. A zip archive is simply a compressed folder which contains your files. Delivering files over the internet this way is very common and makes for faster and consolidated downloads.
To access the sheet music, recordings, video, etc. that is contained within these .zip files, you need to first uncompress or extract it. Nearly every modern personal computer (Windows or Macintosh) comes with software that automatically knows how to uncompress .zip files. Typically double-clicking the file will give you access to the files. Windows users may also be able to select "extract" by right-clicking the file.
If you're still having trouble accessing the files within the .zip archive, there's a helpful article here.
Once you've unzipped the archive, we recommend you make a backup of your downloaded files as they will no longer be accessible for you to re-download after the download key has expired.