Yesterday, we outlined a bit of what we’ve heard about Facebook’s upcoming f8 conference. One big launch will be their official foray into music. Today, we’ve heard more about that launch.

One thing we’ve heard from a very good source is that a key aspect of the service will be “scrobbling”. The term, made popular by Last.fm, means that when you listen to a song, it gets sent to your profile without you have to do anything. I assume there will be a way to turn this off, or a way for you to selectively share songs, but this is a key to the service.

Not that a post-music-to-profile feature should be surprising. Facebook’s core feature is the feed, and music will now make it even more robust. In fact, depending on how popular Facebook Music is, it could end up being one of the biggest sources of feed content.

And I think it will be pretty popular based on the second bit of information we’ve heard. Facebook Music will also apparently offer content resolution between all the different music partners involved. This means that if you’re listening to Rdio and a track goes up on your profile, a MOG user can click on the track and still hear the exact same song in full. Essentially, you’ll only need to sign up for one of the major music services Facebook is launching with to be able to access most content (there undoubtedly will be some songs available on one service but not another, so it probably won’t be fully seamless, but I assume you’ll be able to hear previews regardless).

This content resolution will likely be the most important aspect of Facebook Music. It turns Facebook into the great social music unifier. You can share songs without having to worry if your friends will be able to hear it or not based on what streaming service they use.

It’s not clear what partners Facebook has gotten to agree to this unification beyond Rdio, MOG, and Spotify. It’s certainly possible that while other services will be a part of Facebook Music, those three will be the key ones.

In terms of functionality, we’ve also heard that there will be a standard player that plays music without interruption from page to page as you browse Facebook. Om Malik previously reported on the persistent controls as well as a larger Music Dashboard area. Malik stated that the player would be at the bottom of Facebook, but we’ve heard that Facebook has been testing variations on this player, so it’s not yet clear where it will reside (top, bottom, etc).