Block Access to Designated Pages on Website (PHP Coding)

I have a website which allows visitors to listen to groups of songs on different pages. Let's say a visitor decides to listen to the songs in group # 3. The visitor clicks on the link for group # 3, and is taken to the page. On that page, a player automatically starts and plays the songs (all mp3 files) for the visitor to hear. Group #3 was created by a custom-built program in php which asks me: 1. What group do you want to create? 2. What folder will contain the mp3 files for this group? My answer to the first question was "group3" My answer to the second question was "http:/websitename/group3/group3songs" My problem is that this page is not protected, NOT hidden, so anyone with a little bit of know-how can go to that page and download the songs on to their computer. To be clear, the setup is this: the page "http:/websitename/group3" contains the player and various text and graphics. The page ""http:/websitename/group3/group3songs" contains the list of all the music used by the player on the first page. It looks like this: Index of /group3/group3songs The Beatles-She Loves [login to view URL] Selena Gomez-Hands to Myself Justin Bieber-Love Yourself ...and so on The original programmer who created the code did not realize this. This page, and all others like it on my website must NOT be available to anyone, or else, any moderately aware computer user can simply download as much music as they like, which is illegal. I need to have this situation fixed to prevent this for all pages that offer music to listen to on my site.