Searching for an "index of" usually refers to a direct directory listing on a web server, often used to find collections of files like MP3s. If you are looking for "Greatest Hits" collections for a portable MP3 player, there are several legal resources and directories to explore. Directory Listings & Archives
A "Greatest Hits" index is only useful if it is searchable and organized. Effective indexing requires consistent tagging and folder hierarchies. index of mp3 greatest hits portable
What are you looking to add to your portable index first? Searching for an "index of" usually refers to
Example artists automatically included: The Beatles, Michael Jackson, Madonna, Queen, Taylor Swift, Drake, Beyoncé, Eminem, ABBA, Nirvana. index of mp3 greatest hits portable
Hiby R2 II — A "hi-res" entry-level player that supports FLAC and MP3 with amazing sound quality.