If you’re running iTunes version 12.1 on your Mac running OS X Yosemite, you can display the currently playing song in the Today area of your Mac’s Notification Center. Here’s how to enable it.
The most reliable way to enable the iTunes widget is as follows:
In the iTunes Widget, you’ll see the song and artist displayed, and even a handy button to purchase the song if you’re listening to iTunes Radio. The widget is interactive, so you can play, pause, and rate a song, and even skip forward and backward among the playlist.
You’ll notice I mentioned the above steps are the most reliable way to add the iTunes Widget to the Today panel. You can also add the widget via the “Edit” button at the bottom of the Today panel, however, some users report not having that button available in the panel. The button shows up for us. So this may have been a bug that has been fixed in the latest version of OS X Yosemite.
Thanks to OS X Daily for the original tip.