I've maintained this patch for myself over the years. Now I've made it an actual config option, instead of hardcoded value. PR in #421

My specific use-case is to omit files in ^.*_/.* because that's how I mark the symlink tree hwere I keep various sortings of the db for my own convenience :)

I'm thinking this could be useful to others, in various ways.

This should catch all instances of songs coming from the db...