Hi there,
audiobar is still working with WordPress 3.6. Because of the use of mediaelements there is a little workaround:
1. Add a new custom post type/post or edit one
2. Above your editor you see a big button called “Upload media” (or something like that, i use a german version and there it is “Datei hinzufügen”)
3. Choose your song and upload it
4. DO NOT PUSH Insert into post. This will call the new added audio player. Instead scroll down until you see a little drop box, something like “embedd or link”. Click it and choose the second one (something like “Link to media”)
5. Push Insert into post. Done!
