Meloderic

Meloderic is a dead language that consisted of tone and rhythm, rather than words, phrases, or specific sounds.

Mechanics

Meloderic wasn't so much spoken as it was whistled, hummed, any other music-making verbs one could possibly think of. The type of sound created was less important than the pitch and cadence of the sounds made. 

Evidence of Existence

Most accounts of the existence of this language come from Sounith oral history, though there are markings in caves around the Choral Lakes that have not been deciphered but are believed to be the physical documentation of this language. They do not match up with modern music notation in any way.

Sounith Oral History

According to Sounith oral history, the Tribe of Muted Voices, located around the Choral Lakes, communicated by music alone. They rarely interacted with outsiders, but they weren't hostile. Very little else is known about this tribe.
The Sounith decided to expand their territory, but rather than taking it by force, a small group set out to learn the language of the Tribe of Muted Voices. As melederes, they understood the principles of tone and rhythm in addition to being able to control others with their music. The curious part was that by turning melody into a language of its own, it essentially gave the melederes the limited power of an imperant, allowing them to give Commands to anyone who understood this musical language. It took very few of the Sounith to subdue and enslave the Tribe of Muted Voices and, before long, many of the Sounith could speak the language in order to Command them.
As more of the Sounith learned this language, it began to make things incredibly complicated. Unlike imperant Commands, which only affect the person to which the words are directed, a meledere's abilities affect anyone who listens to their music. Sounith were accidentally (or not so accidentally in some cases) Commanding each other, leading to chaos. The chief declared the language forbidden to be spoken and cursed those of the Tribe of Muted Voices for bringing what he saw as a curse upon his people. All of those enslaved were executed, and the language died with the last of the Sounith who had learned to speak it.