If you've walked eastward on the Community Path starting at the Davis Square MBTA stop (i.e. into Somerville and not toward Mass Ave. in Cambridge), you've walked by a brick mill-style building, now converted to office space, that has large windows overlooking the path.
The Globe says the company could be one of the next big things in the digital music business.
Among other things, the company develops a Musical Brain that helps music streaming services, such as Spotify, predict what songs individual listeners want to hear.
As more and more people get their music online, it could be Echo Nest that helps drive what people listen to.
(Note, in the directory link above we have an old address for Echo Nest. We'll update it.)