This was what PayPal told me to do to sell the music tracks:

1. Enter the details of each item to sell into PayPal's item form.

2. PayPal will generate custom HTML code for each item to sell.

3. Copy the HTML code and paste it into web page files next to each
respective item.

4. This code will result in 'Add to Basket' buttons on the web
pages.

5. PayPal will provide the HTML code for a Shopping Basket Icon to
place in the upper right hand corner of the web pages. This icon will
link buyers to their basket.