PeerTube, the Fediverse's alternative to YouTube, is normally associated with video. However, you can also upload audio files directly to PeerTube. It will accept lots of audio formats including .mp3, .ogg, .aac, .flac, .wma etc.
You can also optionally upload an image file as a thumbnail. If not, audio files will show a black screen by default.
You can find out more about PeerTube at https://fedi.tips/peertube-video-hosting-on-the-fediverse/