Could someone suggest the solution that is easiest for highly non-technical users? I'm talking about users for whom Netflix is too difficult and YouTube crosses that threshold if anything goes wrong. (And don't criticize the users, criticize your UI.)

I don't care how proprietary it is or who runs it, as long as they can use it. I am arranging to have their CDs ripped (they don't use the CD player and saw me using my music library - which is just files in the file system and VLC - and liked the idea of hearing their long-unheard, beloved music) and need something they can actually use. Otherwise, they won't get to listen to their music.

All they need to do is select a track and play it. No other UI needed; it will only confuse things.

In fact, something that handles ripped music and new downloads and streaming would be optimal.