Computers are not supposed to be able to read your mind, but in today’s column we look at two cases where they come pretty darn close. The first is Pandora, a new Internet radio station that knows what kind of music you like. The second — 20q.net — literally knows what you’re thinking.

mp3 fatigue

With their iPods and mixes, today’s music listeners derive an almost perverse pleasure through creating the perfect library or playlist, unique unto themselves.

In this rush for control, however, today’s music listeners often miss out. They forget that there is a whole world of new or relatively unknown music just waiting to be discovered. Too many suffer from what I call “mp3 fatigue” — they succumb to complacency, resigning themselves to the same mp3 library for months on end. Maybe you know the feeling — the world of music marches on, but you and your playlist are stranded in the past.

The ideal technology would act like a good friend who knew your music tastes. It would introduce you to new bands and songs, but only those that you would most likely enjoy. Furthermore, it would still afford you some choice and control over what you listened to. Meet Pandora.com.

Pandora claims to be the result of a music genome project to classify all aspects of music based on sound, as opposed to arbitrary designations of genre, artist or popularity. The result is an ad-free Internet radio station that learns to provide the music that you like.

Open Pandora’s Box

Pandora’s nifty interface is a breeze. Log on to Pandora at http://pandora.com and give it a band or a song you like. It then creates a radio station with music that has similar properties. For example, when I go to Pandora.com and enter Guster, the site plays a song by the British group Fiction Plane, relatively unfamiliar to people in the United States. When I ask, Pandora explains why it plays this song. “We’re playing this track because it features basic rock song structures, a subtle use of vocal harmony, mild rhythmic syncopation and mixed acoustic instrumentation,” and so on. Sure enough, I really enjoy the Fiction Plane song. It has an original sound, a catchy beat and good lyrics. I then add the band to my favorites page, where Pandora.com provides links to purchase the song from Amazon or iTunes.

Pandora tops traditional radio and net-radio stations for a variety of other reasons. First, Pandora delivers stereo music with better sounding audio quality than any other ad-free net radio station. Second, Pandora has a “next button,” so when you get a song you don’t like, you can skip it. Third, since Pandora is based on Flash, all it needs is a browser with the standard free Flash plug-in. You need not fuss with downloading Windows Media Player or Real Player. Pandora’s designers deserve praise for using Flash to provide an elegant, platform-consistent interface that includes album art and a stylish metallic-brush look. Finally, since Pandora is entirely Web-based, your radio stations follow you from computer to computer.

Live and Learn

Most importantly, Pandora learns as you use it. For each song, you can give Pandora a thumbs up or a thumbs down. It then takes this into account when finding new music.

Pandora claims to “Find Music You’ll Love” — and for me it succeeds. After using Pandora almost exclusively over the holiday break, I now have three Pandora stations which consistently crank out new music that I like, often from bands of which I’ve never even heard.

Pandora is a new service and it has room for improvement. I’ve noticed that Pandora often chooses lesser-known live versions of popular songs, instead of the regular one you’d hear on the radio. Also, the Pandora “next” button isn’t unlimited. If you skip about 10 songs in a short period, Pandora gives a message saying that you’ve exceeded the number of skips its license allows.

But as long as Pandora continues to provide the same high quality music for free, these minor annoyances pale in comparison to the benefit of having your very own music guide at your fingertips.

20 Questions: It reads your mind

The same computer learning technology that lets Pandora learn your music tastes also lets the computers at 20q.net beat you at a game of 20 questions. Although this is almost entirely useless, it provides a fun peek at the power of computers to come.

Log on to http://20q.net, think of an object, answer the following yes/no questions and see if the computer can read your mind. My coworker thought of a printer and the computer guessed it well before the 20 question limit. I thought of a record album, and after 20 questions, the computer came up with a record player, which is close enough in my book. Moreover, the more people who use it, the better it gets at guessing. Try it out for yourself — you’ll be doing a service.

Pandora and 20q.net are two examples of technologies that combine computer learning and the Internet, and will hopefully be just the tip of the iceberg. The future will bring more new technologies that learn and adapt to your very thoughts and tastes.

Andrew Leifer is a junior studying physics and is founder of BoulderComputing.com, a small computer consulting firm. E-mail him at andrew.leifer@stanford.edu