Spotify has just announced a significant update to the service, one that focuses on music discovery. It’s all based on the theory that Spotify users complain about not knowing what to listen to, “and artists say they want to connect more closely with fans” – at least according to CEO Daniel Ek.

Soon, Spotify users will be greeted with two all-new features on the service: First, a “follow tab” that allows users to follow “friends, artists, and influencers” in order to get new music recommendations. Second, a new “discover tab” that uses an algorithm to suggest new music based on listening history and follow choices.

With the “follow” feature, Spotify lets users subscribe to the musical preferences of a specific set of artists and influencers. Want to know what Katie Couric is listening to? Well, now you can. How about keeping up with Wiz Khalifa’s current favorites? Just follow him and you’ll see his updates.

As of now, Spotify’s list of “followable” entities totals 76 and features celebrities like President Obama and Ashton Kutcher but is predominately made up of artists. Once you construct your follow list, Facebook friends’ recommendations will also show up in the feed.

The Discover tab is basically a giant recommendation engine that incorporates who you’re following with data concerning your previous listening habits. Help for this feature is provided by various music apps and online music publications.

“Combining the best technology and social tools with content from Pitchfork, Songkick and Tunigo, and many more, Spotify’s Discover feed continually seeks out the most relevant content and brings it right to you,” says Spotify.

The update will be rolling out to all Spotify platforms – the desktop app, mobile app, and new web player – over the next few weeks.

Another noteworthy element to Spotify’s announcement is that Metallica’s full catalog is now available for your streaming pleasure. Yes, Napster-gunning Lars Ulrich is letting people listen to his music for free (mostly). This seems to be the culmination of the “I don’t really give a sh*t” approach he began taking back in 2008.

“Metallica has always tried to be in control of the way we present our music to our fans, which is why we’ve waited to see the way these online retailers and streaming services operate and gauge the overall fan experience before deciding to include our music” said Lars Ulrich. “We now feel that Spotify not only has a proven track record, but is by far the best music streaming service. We are beyond psyched to unleash our music through their platform.”

Oh, and you can also “follow” Metallica’s recommendations if you want.

Today, Spotify announced 20 million users and 5 million paid subscriptions, meaning that the company has grown their paid user base by two million over the course of the year.