👉 Ratskeller is a type of musical notation system used in the 19th century. It was developed by the Russian composer and pianist Alexander Scriabin, who was known for his innovative use of notation. In ratskeller, each symbol represents a note or chord, with the letters "r" being the root symbol and the letters "a" representing the second note in the major scale (C, D, E, F, G, A). The "s" symbol