Compendium Helper is a modern website that uses the information from your Spotify library to build a powerful playlist, representative of your library as a whole, called The Compendium. It is a quick way to generate a playlist that distills down your 'Liked Songs' list into something smaller and more manageable, while still including all the artists (and many of the songs) you know and love.
Compendium Helper chooses one song from every artist that is represented in your Spotify library, creating a playlist that includes all the genres and all the artists that you love the most.