Vernacular

Music is the vernacular of the human soul.
~ Geoffrey Latham ~

Now, when I first came across this I had to look up vernacular. So just in case you are expanding your vocabulary also:

ver·nac·u·lar (noun)
1. The standard native language of a country or locality.
2. The everyday language spoken by a people as distinguished from the literary language.
3. A variety of such everyday language specific to a social group or region: the vernaculars of New York City.