I have uploaded the files brown-haired maiden.mp3 and brown-haired maiden.M4A into the folders:
Images
Images/audio

I set the local audio folder in Allvideos version 6 to Images
The following is a snippet from my home page www.LPMS.org.uk. I have cleaned out the html tags as previously suggested by Fotis to a related query.
{mp3}brown-haired maiden{/mp3}
{m4A}brown-haired maiden{/m4A}
{audio}brown-haired maiden{/audio}
{mp4}Donald Camerons powder Horn{/mp4}
The mp4 file (also in the images folder) plays ok.
But for both the mp3 and the M4A files, I got a message from the front end "This type of audio file is not supported"
The line with the {audio} tags is ignored.