Today's update for Groove Music, (April 1, 2017), is really starting to show elements of the up and coming Project Neon design feature.

New Groove Music update includes hints of Windows 10 design refresh

Transitions and Translucency:

Click image for larger version. 

Name:	1.png 
Views:	0 
Size:	387.7 KB 
ID:	127632
Click image for larger version. 

Name:	2.png 
Views:	0 
Size:	456.6 KB 
ID:	127633
Click image for larger version. 

Name:	3.png 
Views:	0 
Size:	552.5 KB 
ID:	127634

You can see a hint of my desktop 'rainbow' colors through the translucent Groove navigation pane:

Click image for larger version. 

Name:	4.png 
Views:	0 
Size:	966.7 KB 
ID:	127635