Colorized 'play' button in front of the currently playing music
I think it could be good to visualize which music is playing directly in the main screen, when you browses libraries or playlists.
Here is what I mean (the button could be red or green because the music is currently playing) :
![2019-05-15_13h14_20](data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==)