With the new media apps in macOS, one thing I miss is the ability to use a system-wide controller to play and pause music, to skip tracks, and to change volume. There used to be a lot of these, and for many years I used Sizzling Keys, which has been “retired.”
The Now Playing widget in Notification Center’s Today View is a partial replacement, but it only offers limited features. You can pause or play music, skip ahead and back, and drag a playhead, but nothing more.
It seems that this widget could easily be improved, at least adding a volume control, or, perhaps, add an Up Next button, like in the MiniPlayer, and allow users to rate/love music as well. (The MiniPlayer’s volume control is behind the AirPlay icon; you can adjust the volume for each device where you are streaming music, or for playback on your computer.)
And, no, I don’t want the MiniPlayer visible all the time; with Notification Center, I can just use a hot corner to display it. I have the top-right corner set so when I move my cursor there Notification Center displays.
It’s possible that adding an Up Next button, and the list it displays, wouldn’t work in this location, which is designed for static elements, but there could be at least a volume control in the Now Playing widget. Because when you’re playing music other than through your Mac’s speakers, the volume keys on the keyboard don’t affect music playback.