In this web site, this process works for uploading and embedding audio files with player controls:

Prepare the file and upload an audio file

  1. Save audio file as .mp3. If that isn’t an option, save it as .m4a.
  2. To convert an .m4a file to .mp3, open it in iTunes and add it to a Playlist.
  3. Export the playlist to .mp4 (or .mp3 if it’ll let you).
  4. In the Finder → File list, change the file extension from .mp4 to .mp3.
  5. Upload the file into WordPress.
    • Do this from the Post or Page you need the audio file to display on, usig the Upload/Insert button.
    • Drag and drop the file to the upload screen.
    • In the Show screen, fill in the title and caption fields, then click the NONE button for link.
    • Click insert into Page (or Post).
  6. If the player does not show, but a link shows, then in the HTML tab of the editing screen, remove all code from around the http://…address for the file. For example:
    • By doing this, the Audio Plugin will provide a control bar when viewed live.

Add Video

  1. Upload file to YouTube.
  2. Click Share->Embed and copy the iframe code.
  3. Paste code into the HTML tab of your Post or Page
  4. Either remove or update the width and height values.
  5. Click UUpdate.