[Zubersoft]

No, it's not possible to do that because I did not want the database stored on an SD card as it would cause severe problems if the user removed the SD card and then loaded MobileSheets, as MobileSheets would then revert to using internal storage with a new database instance, and if you then plugged in the SD card, it wouldn't know to switch back to the SD card database, and could potentially overwrite the file on the SD card. I've also seen SD cards go bad for users many times over the years, and that would cause the library to be lost if the database was only stored on the SD card. There are also issues with read/write speeds with some devices/SD cards which would dramatically impact the disk I/O with the SQLite database. 

As far as the internal storage, the database file is probably < 50 MB even if you have thousands of songs in your library.

If your storage location is set to the SD card, then the database is stored under /storage/emulated/0/Android/data/com.zubersoft.mobilesheetspro/files

Mike