Solresol

Solresol (Solfège: Sol-Re-Sol), originally called Langue universelle and then Langue musicale universelle, is a musical constructed language devised by François Sudre, beginning in 1817. His major book on it, Langue Musicale Universelle, was published after his death in 1866, though he had already been publicizing it for some years. Solresol enjoyed a brief spell of popularity, reaching its pinnacle with Boleslas Gajewski's 1902 publication of Grammaire du Solresol.

Today, there exist small communities of Solresol enthusiasts scattered across the world.