**Sure!** It's not complete, but MPS is completely useable for basic music queries right now. Hopefully most of the bugs have been ironed out as well...
**I thought it would be fun**. I also wanted to be able to play my music without having to be at the whim of someone else's algorithm (and music), and playing just by album or artist was getting boring. I also thought designing a language specifically for iteration would be a novel approach to a language (though every approach is a novel approach for me).
**Music Playlist Script (MPS) is technically a query language for music files.** It uses an (auto-generated) SQLite3 database for SQL queries and can also directly query the filesystem. Queries can be modified by using filters, functions, and sorters built-in to MPS (see mps-interpreter's README.md).
**No**. Technically, it was designed to be one, but it doesn't meet the requirements of a scripting language (yet). One day, I would like it be Turing-complete and then it could be considered a scripting language. At the moment it is barely a query language.