At a recent dinner party my wife and I hosted our guests brought wine and flowers and the music for the evening was provided by the shared taste of millions of iTunes users. In the past weâe(TM)ve relied on our CD collection or a handcrafted playlist of tunes from our computers piped wirelessly to our stereo in the living room. But that evening I thought Iâe(TM)d use the new Genius Playlist feature of iTunes as a digital DJ.

Much like the online music sharing service Last FM, the new Genius feature looks at a song youâe(TM)re playing in iTunes and then suggests music in your playlist that complements it nicely. Of course, it also offers to sell you additional music which would also get along with your currently playing tune like Sarah Palin and the NRA.

In my case I started the ball rolling with Miles Davisâe(TM)s âeoeBlue in Greenâe . The Genius Playlist suggested Lester Youngâe(TM)s take on âeoeThese Foolish Things, âe Wynton Marsalisâe(TM)s version of âeoeAutumn Leavesâe and âeoeAt Lastâe by Ella Fitzgerald and Joe Pass along with 47 other well- considered choices from my jazz collection. So, how did it do that?

The actual algorithm or method Apple is using for the Genius feature is a black box, but it basically looks at the buying habits and (anonymously) the playlists of millions of iTunes buyers and users. From that collection of behaviours and associations, it comes up with a dynamically improving guess at which songs are most like other songs. It then builds playlists and makes recommendations accordingly. Itâe(TM)s also encouraged me to spend about $50 on new music in the last week.

Okay, so thereâe(TM)s a ton of ideas to tease apart here.

In a previous column I discussed the idea of the âeoecommon good,âe a shared, inexhaustible digital collection of wisdom, links, images etc which is created collectively and sometimes collaboratively by web- users. The collection of links on delicious, the articles on wikipedia or the photos on flickr are examples. With thousands or millions of people contributing freely it takes little individual effort to, jointly, create a vast, self-correcting resource.

The Genius feature creates a near effortless common good. All you have to do is listen to music (you donâe(TM)t have to buy anything) and share your taste anonymously. We all benefit from the shared digital DJ that sharing evokes – and when we do buy tracks, so does Apple, and so do the music labels and artists. In fact, the Genius playlist turns out to be word-of-mouth on âe~roids. On lastfm.com, a whole community is built around musical taste sharing, which you can do publicly, building a network of musical friends, and a music shopping wishlist in the process.

That means that, despite the hand-wringing on the part of the music industry, the free sharing of music can actually result in increased music sales – that the common good can actually be good for business. It can also, I think, be good for non-profits and causes.

Imagine a Genius playlist for progressive websites. Based on the stories you read and anonymously share with others you get a list of other stories you might enjoy and a list of charities you can support to aid in the causes you care most about. That charitable common good is built simply by doing what you do now, such as read stories like this one. But, a little effort, aggregated, becomes a powerful tool for change, in musical listening habits or in society. It just depends on whatâe(TM)s harvested.

I think weâe(TM)ll see more of this collective behaviour harvesting coming in the near future. Weâe(TM)re already seeing it on even purer levels with the Dash Express, a GPS unit that combines traditional traffic information with real-time traffic information gathered from the actual driving experiences of other Dash Express users. All the drivers have to do is drive, and share.

So, whether you want to buy, say, Matthew Goodâe(TM)s new album, check the traffic between you and the concert hall or support a cause the Canadian musician has gotten behind, I think crowdsourced advice grown from the simple act of sharing passion will begin to inform your choices soon in a way it has never done before. Just thought Iâe(TM)d share that.

wayne

Wayne MacPhail

Wayne MacPhail has been a print and online journalist for 25 years. He was the managing editor of Hamilton Magazine and was a reporter and editor at The Hamilton Spectator until he founded Southam InfoLab,...