A website / service I use almost anytime I sit down at a computer for an extended amount of time is www.pandora.com.

Pandora is an online music streaming service that lets users pick “stations” based on songs or music genres.  Follow up songs are based on the type of song or genre selected initially and may not be by the same musical group or performer as the initial selection. If a user doesn’t like the follow up song the option to provide feedback (a thumb’s down) is available and the song is skipped.  Pandora remembers your likes and dislikes and makes future selections for your station accordingly.

Technically Pandora is reviewing some 400 different attributes combined into some 2000 focus traits about the song to determine the next selection.  Traits including the amount of bass, vocals, harmony, pitch, instruments, tempo and more. The first time I ever used Pandora I typed in the name of a favorite band.  The initial song was one of the band’s recent hits and was followed by 9 of the next 10 songs that I enjoyed.  They have over 700,000 tracks available to choose from so the odds of finding a song you like are pretty good.

Pandora currently is free (ad supported) and also has a paid subscription service that removes adds.  Both versions require a valid email address and registration / sign-in prior to use.  The free version allows 40 hours of music per month and is broken up into segments (approximately 30-40 minutes) separated by television type commercial adds.

Pandora also has applications for the iPhone, Google’s Android mobile operating system and other mobile devices.  Pandora is the 3rd most downloaded Free App of all time from iTunes behind Facebook and Google Earth.

The company itself still hasn’t turned a profit but filed a 100 million dollar IPO in February of 2011 after posting revenues of some $55 million in 2010 and $90 million during the first 3 months of it’s 2011 fiscal year.  More info on the company can be found here.

Due to the variety of music available and availability 24 hours a day on the internet I haven’t purchased any music since finding Pandora.  Try it yourself…the price is right.