On Language and Art

There are multiple connections between language and art. One can be said to start with language and go into art, or making art with language. The term "language arts" can refer to rhetoric and literature (including prose, poetry and theatre). Calligraphy or constructed languages like solresol that can be expressed in music are other aspects
The other connection starts with art and goes into language, or uses art to communicate. There could be said to exist a communicative purpose to most art, since the artist often wants to influence the receiver or transmit a feeling or concept, but the relation can perhaps be best observed in artists like Kandinsky and Wagner. Kandinsky could be said to have tried to create a kind of non-linear language consisting of colours, lines and dots, expressing feelings and other abstract concepts. Wagner wrote a lot of music for the opera, the equivalent of the cinema of that time, and even when he wrote independent pieces of music they often had a theme that was supposed to evoke quite specific images in the mind of the listener.
It is maybe easier to appreciate the closeness of art and writing than art and speech. We certainly know much more about the evolution of writing than about that of speech due to the permanent nature of the former. It is clear that many letters developed from depictive symbols, A for instance, was initially a bull's head and D a fish. With cave paintings and old writing systems it is often hard to determine whether the inscriptions are there primarily for communicative, magical or decorative purposes. Then of course there is the magico-decorative uses of letters on weapons or as tattoos.
There might very well be a similar common origin to speech and music as to writing and visual art, but since speech predates writing with thousands of years, it is unlikely that we will ever know.