The modern use of recordings of various styles of music and kinds of musical instruments is a big time and effort saver. Parents who want to enroll their children in music classes and private lessons in the future should plan ahead, including taking such introductory classes themselves.
In my own teaching studio, I have always required at least one of the child's parents to take a month or two of private lessons on the instrument that is to be the child's, before the child himself enrolls. I also require that parent to agree to practice the instrument at home for a few minutes daily, in the presence of the child.
Parents are also encouraged to take their childrent to attend performances of live musicians, particularly those who play well the instrument the child is learning.
These are some of the ways I personally implement and apply the concept of "language learning" to learning to play a musical instrument.
Very nice, well-written post, as always!