« TagSoup 1.0 released | Main | Nice parodies of "Mac hipper than PC" ads »

Opening Pandora's (music) box

Free online music and algorithmic suggestions.

I've been listening to music on the Pandora internet radio site for a while now. After creating a free account, you define a "channel" by naming one or more artists, and then they play whatever music they have by that artist and music that they judge to be similar. Similarity rankings are based on attributes they've assigned to different artists and judgments by their listeners who've clicked the Thumbs Up or Thumbs Down icons available with each song. Of course, links are provided if you like something enough to buy it, and ads for music include links to let you add that artist as a new channel in your collection.

Sometimes the attributes they judge by are not the attributes you're interested in. I created a channel called "crunchy art rock" that started off with Radiohead and Beck because I like music that balances rocking guitars with less melodic electronic noise (I still don't own Roxy Music's first album, and really should pick up a copy), especially the old school analog electronics. When that channel started playing lots of quiet music with obscure lyrics that were "sensitive" to the point of whining, I realized that that what Pandora found that Radiohead and Beck had in common was different from what I liked about them, so I didn't listen to that channel much. Recently, adding Sonic Youth and Pere Ubu to that channel has helped, although I hear a lot of fairly generic "alternative" rock there now.

An even funnier misjudgment came when I added Doris Day's name to a channel of mostly 1940's swing that I started with Artie Shaw's name (I've recently gotten to appreciate him more, but not enough to run out and buy a CD), because what little I'd heard of her early singing was surprisingly good. Pandora seemed to consider Day's later, more well-known hits as representative, and put songs by the Carpenters and Barbara Streisand on the channel, so I swiftly removed Doris Day. I usually listen to the "jazz (mostly bass)" channel that I started with the names of bass players who have fronted groups; it's dominated by small group hardbop and makes good listening while working.

My brother suggested that I try last.fm, a similar service, to compare the wisdom of their algorithm for guessing what I'd like with Pandora's. I didn't like last.fm as much, but not because of their algorithm. First, they make you download and install some client software before using it, which would have seemed reasonable enough three years ago but already seems old-fashioned—Pandora has a much more Web 2.0 approach, keeping all the logic and interface on the server (and providing one exception to the rule that Flash sucks). Secondly, when you've listened to enough music on one of these services from an artist you're familiar with, you realize that the service licensed whatever they could, which may or may not be a large sample of that artist's music. It's fun to talk and guess about the algorithm they use to suggest music to you, but when you listen for more than an hour or two, the size of the pool that they can draw from based on your criteria becomes much more important than the magic predictive algorithm. Otherwise, you end up listening to the same things over and over. I was also annoyed when a last.fm search for "Ray Brown" didn't turn anything up, but an artist that they suggested as similar to Charlie Mingus was the "Ray Brown Trio"—if last.fm's ability to search artist names couldn't match up "Ray Brown" with "Ray Brown Trio," then I can't have much faith in their predictive algorithm or even the overall architecture of their system. (For fun, I asked last.fm what artists were similar to the Beatles, and they listed the Rolling Stones, Radiohead, Led Zeppelin, and the Eagles. I guess that either being English or having multi-platinum albums makes you similar to the Beatles.)

Pandora knows that the size of their collection is an issue, because every now and then I get an email mentioning new material they've acquired that fits in with one of my channels, so I may go back and listen to that channel after ignoring it for a while. Another neat touch is that they make it easy to email anyone about a channel, and the email includes a URL that lets the recipient jump right in and listen to that channel. (Let me know if you'd like me to have them email you any these channels.) They don't seem to have any classical music, which would also be nice for work purposes. Even big-name performers like Gil Shahan and Yo Yo Ma get no hits, and when I searched for "Ludwig van Beethoven," after having me confirm that it was an artist name, Pandora asked me if I meant "Camper Van Beethoven."

If I was younger, I'd play one of those "look how eclectic I am" games on Pandora and create a channel with several artists from around the world who have nothing to do with each other to see what Pandora's algorithm comes up with, but I'm more interested in finding good music to listen to while working that isn't too distracting but may lead me to discover new music in a particular category. For discovering international music from outside of my usual categories, I'll stick with the streaming audio of the WFMU shows Give the Drummer Some and Transpacific Sound Paradise.


(Note: I usually close comments for an entry a few weeks after posting it to avoid comment spam.)

Made my day: "Radiohead...Beck...adding Sonic Youth and Pere Ubu to that channel has helped..."

I haven't clicked Danny's trackback to see if he feels the same way I do, but from the lead-in it seems that he does...

To both read your analysis, and notice that you have such FANTASTIC taste in music brings a smile to my face. Anybody who can list out and compare Radiohead, Beck, Sonic Youth, etc... and be able to understand how they are related, and how they are not is just fanastic in my book :)

Nice! :D

For what it's worth, the Pandora folks openly acknowledge that it works better if you specify songs rather than artists for the radio stations, for reasons that your post suggests.

Thus, if you don't like Doris Day's later work, you should specify a few specific early Doris Day songs that you do like. Also, the thumbs up/thumbs down thing is only relevant within a given channel, so you don't necessarily have to feel like you're permanently harming Pandora's likelihood of giving you something you "sometimes like" -- if it doesn't fit on your idea of a channel, give it a thumbs down and you can make another channel where it does belong.

I'm not shilling for Pandora -- just sharing some stuff I've picked up along the way.

Thanks Joe, this is useful stuff to know.


My understanding is that last.fm suggest to you songs that other people like who listen to stuff you like – the Web 2.0 “wisdom of the crowd” thing and all that. Of course, the result of that approach is that all popular music is deemed similar to all the other popular music, within rough genres – hence the Beatles being similar to the Rolling Stones, Radiohead, Led Zeppelin, and the Eagles.

Also, having to download software, to me, makes more sense than the Pandora approach. With Pandora, I’ve got to have a browser open, and I can’t listen to my own music. With the last.fm client (or one of the many third-party plugins to connect various music/media players to the service), your playlist just piles up as a side-effect of your regular music listening: no need to change habits. So both approaches have their pros and contras.