They said it couldn't be done: Teaching robots good taste. "Actuality" visits Spotify, where algorithms tell 75 million users what to listen to. Then, Tim and Sabri talk with a world-touring musician and a critic to see if this trend will save the arts — or doom them."Actuality" is brought to you by Marketplace and Quartz. It explores the inner workings of the new global economy, combining the best of our economic smarts. Subscribe to the bi-weekly podcast on iTunes or your favorite audio app.