I installed the Media Entity module for Drupal 8. I thought it would somehow facilitate adding Mp3, etc, as Media does in Drupal 7, where I could specify a media player type for an audio file. (And things work fairly well.) I am updating my site to Drupal 8 and it seems the Media Entity module only acts as an API. Maybe I just need to wait for an official Drupal 8 release before I get too far in the weeds with media?
Since I am grabbing Mp3 files from my previous site, ideally there would be a media field to which I can, in code, just add the field info, with the rendering of the field being determined by the form display settings.
Anyway, I am sure a lot of people are trying to figure this out in Drupal 8, so if anyone has a good approach, I am all ears!