Just as the word "cat" describes a particular type of animal; however it is as if some people were to insist the description should also include dogs.

No (however, if you were to describe a cat and a dog to an alien who had never seen either, I think you'll find your descriptions would be remarkably similar). Most people know a cat when they see one. It has 'cattiness'.

A song is just words set to music. The journey (or 'process') it has undergone before it reaches my ears is irrelevant when I am in listening mode (interesting and worthy of study though that journey may be). It may have been written yesterday or 300 years ago - I know a folksong when I hear one. It has 'folkiness'.

PS: The lawmakers know who they are. Their feigned puzzlement doesn't fool anyone.