Media Control appears as a toolbar button, and is a simple dropdown to control media players from Amazon, Spotify, Groove (formerly Xbox), and YouTube (HTML player only).
For each you can play and pause, and if listening from a playlist, go forward and back within the list. Spotify allows additional control of repeat and shuffle. YouTube allows additional control of playlist, autoplay, and mute functionality. Amazon and Xbox allow for a mix of the two. You can also click the external link button to go directly to the tab.
For each tab with a player you have open, a control will appear. If for some reason it is unable to control directly there appears a large button to go to the tab directly.