I suppose you mean 15:00 instead of 14:05, but that's not so important.
You're protocol is right, but I have my doubts about the medium e-mail.
We're talking about audio-files here and they tend to be big. Any attachment to a mail will be about 50 % bigger in filesize due to coding. Since systems are pretty quick nowadays, no problems between two people, but if the organiser
has to load all those pieces, zip them, and upload again, this would take substantial time.
Another medium is, if one has, the server of one's own website.
I use the principle, that if filesize > 1 Mb (such threshold can be custom set of course), then I don't attach, but use a subdirectory, created on my website (but not linkable from there), where I can upload the file, and send a mail to the receiver with just the download-link in it, so without the content.