It turns out .ogg files don’t play from iOS browsers, so I opted to change the format to .mp3. Here’s how to do that using `ffmpeg`
Open your terminal
Install ffmpeg
brew install ffmpeg
cd to folder with .ogg files
Loop through all the .ogg files, changing them to .mp3 files
for i in *.ogg; do ffmpeg -i "$i" "${i%.*}.mp3"; done
This was useful to me because iOS (iPhones, iPads) don't support playing .ogg files in their browsers