After you sign up, you can:

• Browse and listen to a whole ton of songs that you can't see otherwise.
• Read "friends-only" article entries.
• Do you know me better than I do? Probably. Help me fill out a profile.
• Leave comments on articles, songs, and song audio clips.
• Get down with your bad self.

After that, you can always log in/out by clicking on the button in the top-right corner of the browser:

Now, go create an account.