That depends on the volume of posts you are going to have for recordings and regular posts. if you are talking about a few of each then using the built-in categories and tags will do and you can leverage all of the built-in functions for tags and categories, otherwise there is no harm in using your own taxonomies.
And as for the individual recordings info( date, lenght) if its not needed to be searchable you can use the post’s custom fileds for that.