Spotify’s progress in sorting its library of 35 million songs can be traced back to The Echo Nest, a music intelligence company that was created within the MIT Media Lab a decade ago. Spotify bought The Echo Nest last March in what was reported to be a $100 million deal. Jim Lucchese, CEO of The Echo Nest, tells Tech Insider that his team of about 70 people are focused on delivering “the right listening experience at the right time” within Spotify. They do this by analyzing the makeup of every song, how people are talking about music online, and how people are listening to it. While the company continues to work with clients like Rdio, Microsoft, Sirius, and Vevo, as it did before it was sold, its most cutting-edge work is developed and honed for Spotify…