Why can't you rewind or replay a song on Pandora.com? And when you type in the name of a song you want to hear, why will a different (but, yes, similar) song start to play instead? Argh, it's so annoying! But, it turns out, it's also the reason why the Web site can play those songs for free as a Webcaster. Read more...

There are many steps (and sometimes many years) before a good business idea becomes a good business. For the Web radio site Pandora.com, those steps included raising over $1 million from investors and spending five years building the Music Genome Project before it was ready to launch. Read more...

Sure, Web radio sounds great when you're sitting in front of your computer, plugged in to the Internet. But what do you listen to on your commute to school or during your daily jog? Pandora's Tim Westergren says the increased popularity of mobile devices, like smart phones, has in turn boosted Web radio's reach. Watch the latest video in our Brains & Beakers series below.

In the second video from his Web radio workshop, Pandora founder Tim Westergren talks about how his Web site builds its song playlists and how webcasting is becoming more popular than broadcasting.

For our latest Brains and Beakers workshop, Youth Radio hosted Tim Westergren, founder of the online radio service Pandora.com. Tim studied recording technology at Stanford and has worked in the music industry for 20 years as a composer, musician and record producer. In 1999, during the height of the dot-com boom, he noticed that people were listening to more and more music online and wondered if there was a way to create a personalized web radio station that plays only songs that matched an individual listener’s tastes.

To do that, he launched the Music Genome Project – a collection of songs that have been analyzed one by one according to 400 musical attributes, like rhythm, harmony, and instrumentation. Their musical DNA, in other words. When you type a song you like into Pandora, the Web site plays songs with similar DNA. Call it compiling sonic taxonomy, sequencing musical phylogenetics… or just playing one hit after another.

In the first of five videos, Tim talks about how Pandora’s in-house musicians break down every song on the Web site into its musical characteristics. “Any piece of music, whatever the rhythm is, we can understand it through some combination of these attributes,” he says.