The Computer Science Side of Pandora Internet Radio

The Internet Radio service named Pandora claims it can guide you, the listener, to new (or old) music that you enjoy based on a song or artist that you like. Upon navigating to the website (www.pandora.com) the user types in a song, artist, or genre of music to the web-based music player. This creates a "radio station" that will in turn play music Pandora deems similar to the song or artist originally entered.

Pandora is based on something called the Music Genome Project. Each song in the Genome database has been analyzed by a trained music analyst using up to 450 musical characteristics to determine the genetic makeup of the song. Some of these traits include a song's arrangement, melody, rhythm, beat, tempo, and voice. When the user enters a song to create a "radio station," Pandora runs an algorithm to compare every song in the Music Genome database to the one entered, identifying songs with similar characteristics. These songs are the ones played next on the "radio station." The user can further refine the station by pressing the "thumbs up" or "thumbs down" buttons on a particular song, providing input that tweaks the algorithm so that the station plays more or fewer songs similar to the one playing, respectively.

Pandora stores the listener's user data in his or her computer's Flash local storage. This helps Pandora recognize when the same listener returns to the site. Pandora also stores songs that have already been played in a specific listening session in the users computer's Flash local storage so the same songs do not get chosen multiple times in a session.

Aside from using user input to refine his or her personal radio station, Pandora uses the "thumbs up" and "thumbs down" feedback from millions of listeners to further refine its algorithm. This allows Pandora to make better informed projections about what songs might fit a listener's taste.

References:

Content:
http://computer.howstuffworks.com/internet/basics/pandora3.htm
https://www.fastcompany.com/1808123/how-computers-curators-and-users-create-pandoras-playlists
http://www.nytimes.com/2009/10/18/magazine/18Pandora-t.html
http://www.nytimes.com/2014/01/05/technology/pandora-mines-users-data-to-better-target-ads.html

Images:
http://images.dailytech.com/nimage/22015_large_Pandora.png
https://images.iskysoft.com/mac-audio-recorder/pandora-site-signing-in-problems-810-524.jpg