Hey @Romeo Crow21,
Currently, we do not support uploading mp3 files directly to your Tribe, but we do support embedded SoundCloud links for audio.
It's worth mentioning that many of our customers requested to be able to customize the extensions their members can upload. If we see more people are interested in this feature, we'll add a feature which will let admins define file types or extensions for each content type.
As a side note, security is the main reason we don't let members upload more file formats. Some formats can contain malicious scripts that may harm your community members.