The "music directory" is where you store your music files.
MPD stores all relevant meta information about all songs in
its "database". Whenever you add, modify or remove songs in
the music directory, you have to update the database, for
Depending on the size of your music collection and the speed of the storage, this can take a while.
To exclude a file from the update, create a file called
.mpdignore in its parent directory. Each
line of that file may contain a list of shell wildcards.