Thanks Brent, that was the problem; we had it set for the player for all "media".
I did think that the settings might have been in MIME types, so you can define how each file type is handled by format, so if the file is an MP3 it could be opened in one player, or if it was MP4 a different player.
With the pop out audio player you can allocate a picture (the default is a speaker), but could that be made dynamic in the same way as header and footer (or if you can already, what is the format)?
For example you have a recording called "JBS.mp3", by teacher "JBS", and in the folder "images" you have a picture "JBS.jpg", so following the logic from the footer, the picture you'd write "images/{{teacher}}.jpg" such that when the popup opens it shows an image tailored to that audio.
If I type in "images/{{teacher}}.jpg" to the footer box it shows the correct path (although the file is lower case and the artist has upper case letters), but not when I do it in the image box. Is that box not included in the database search like the footer box?