[fziegler]

The crucial point now seems to be that I imported songs by

• Import > System file manager > Explorer
  

That way, I was able to open my special file manager app 'Explorer' which allows me to access my sheet music directory on our home NAS via smb://xyz/. All files I create with my computer (e.g. PDFs from a notation software or an edited scan) are stored in that directory. I was happy to be able to directly import from that storage into MSP by having open multiple tabs in that file manager and copying a remote file via SMB to the local library directory. And thought that MSP then should behave the same way as it does with local files that were there from the beginning.

I didn't realise my problem came from that point. I thought it had to do with some odd behaviour from MSP in cooperation with that file manager app.

Let's see what you might need to know:

• permissions: storage concerning media files, camera, no permission for locality determination
  
• settings: MSP is not meant to manage my storage; the MobileSheets directory is placed on a microSD card; the data base is not in the MobileSheets directory; original files aren't deleted after copying (but greyed out); subdirectories may be created for songs (but greyed out); my problem has nothing to do with any cloud system (Dropbox, Google, OneDrive);
  
• I start by Import > system file manager or by New > Add file > system file manager
  
• I get a selection of different sources, amoung them my additional file manager 'Explorer' which I select
  
• Explorer opens up with its different tabs, I select the SMB tab to access my NAS, copy a newly created file, switch to the tablet's local directory tab and put the copied file into the appropriate subdirectory (say 'Jazz standards'), immediately select it for importing and hit [OK]
  
• I get MSP's import dialog with a deduced song name (from the file name) and continue to fill in the data fields, import the song and that's it.
  

I didn't expect there was anything needed to be copied as everything is on place when terminating the import. But of course only then - the file wasn't locally accessible when starting the import procedure.

As you say only importing local files will help against copies, I may go back to my initial handling - the same way McAroni does ist.

I now learned as well that I may be able to avoid subdirectories being created when unchecking that greyed-out option. That may help against subdirectories as well when I import files directly from the camera (which happens every now and then in the band - in that case the subdirectories have names derived from the momentary date).

So, you didn't solve my issue but shed a lot of light onto the thing - and I'll be able to work around all that stuff. Thanks a lot!