Non-Linux FOSS: Control Web-Based Music!
I like Pandora. I like it because it doesn't require me to know anything other than whether I like the current song. I'm sure other music services offer more features or a larger catalog, but Pandora is simple. So am I.
One of the frustrating things about using the web-based version of Pandora is that getting back to the proper tab can be frustrating. Thanks to an oddly named open-source tool for OS X, when I'm on a Mac, I can map keyboard shortcuts to the web player even if it's in the background.
The BeardedSpice program is open source and available to download here. At first, I wasn't sure how to configure it, but that's because there's very little to configure. Once I set the keyboard shortcuts I wanted, it's just a matter of pressing them while the music is playing! It's simple, effective and it's free (both kinds of free). If you use OS X, grab a copy today!