Add locally stored files to collection?

[manisfive]

On my Galaxy S3, I want to populate the Collection/Artist tab with all locally stored music files without having to go through each track on each playlist on the phone, one by one, and adding to collection.  I have have plenty of storage, and the feature that downloads a track as it is added to a pinned playlist is working properly, but there is no easy way to shuffle all currently available songs (or the combined contents of every playlist? that would work as well).

This is the one lacking feature.. hopefully I'm just overlooking it.

Edit:  ehh figured it out, though it's not at all obvious. On the desktop app, create a playlist folder, put relevant playlists inside, creates an 'all tracks' option within the folder on the phone interface. That'll do, but, pretty arcane, yeah?