There was a custom app here; Passcode Song Downloader, made for musicians to sell music on their own websites. The app hid music download files in subdirectories. When a music fan paid or responded to an offer, the musican / site owner could send them a code and a link to download a track or entire album.
It worked. Musicians would get 100% of all payments. But, it was too complex for people to try out, in any number. When musicians sell elsewhere, they pay a 25% to 60% + sales commission. Now, most music traffic is streaming. The music downloader app has been retired. If anyone is still interested in how this code worked, you can:
The old passcoder looked like this:
