This is a program that will sync one source directory tree with a destination and find all music files that match some criteria in the source tree, "Genre" will be the first criteria implemented.
It then updates the source tree with any changed files from the source and will delete files from the destination that are no longer available in the source.
Assume you have a complete media library and you want to extract only music files which has "Genre" equal to "Rock" or "Blues".
musicfilesync --from source --to destination --genres=rock,blues