Valarin
In J. R. R. Tolkien's fictional universe of Middle-earth, Valarin is the tongue of the Ainur. As angelic beings with the ability to communicate through thought, strictly speaking the Valar had no need for a spoken language, but it appears that it was adopted as part of their assumption of physical, humanlike forms.
Valarin was extremely alien to the ears of the Elves, sometimes to the point of genuine displeasure, and very few of them ever learned the language, only adopting some of the Valarin words into their own Quenya. The Valar learnt Quenya instead, and used that to converse with the Elves, or with each other if Elves were present. Valarin seemed to use long words; for example, the Valarin word for Telperion, Ibrîniðilpathânezel, is eight syllables long. The Vanyar adopted more words from Valarin into their dialect Quendya than the Noldor, as they lived closer to the Valar. Some of the Elven names of the Valar—such as Manwë, Ulmo, and Oromë—were supposed to be modified (and shortened) versions of their Valarin names.
At least one word in the Black Speech, nazg "ring", seems to be borrowed from Valarin naškad (Melkor was a Vala and Sauron was a Maia, so they knew Valarin).
Valarin is unrelated to all the other Languages of Middle-earth as it arose outside of Arda, and except for a few words (mainly proper names) nothing is known of the language. Before it, the only form of language was the Music of the Ainur, the purest form of language, as it was thought itself, with no need for reference; Each thought was a definite article in and of itself, and as such, the Music was entirely self-sufficient structure. Eru only showed the Ainur their music in a different form by adding the final note to their song: Eä, "Be".
Tolkien seems to have debated over the years whether or not to give the Valar their own language; some of his writings indicate they did not have their own tongue, but this was later changed. The result seems to have caused some retconning and possible inconsistencies; for example, whether Manwë's name is from Valarin or the Quenyan root for "blessed," as some writings claim.
In older versions of The Silmarillion and in the Lhammas, Valarin is further subdivided in Oromëan, Aulëan and Melkian. In this conception, all Elvish languages arose from Oromëan, while the Dwarves spoke Aulëan and the Black Speech was Melkian; this view was later dropped, however.