Tonality is a system of music in which certain hierarchical pitch relationships are base on a key "center" or tonic. The term tonalité originated with Alexandre-Étienne Choron (1810) and was borrowed by François-Joseph Fétis in 1840 (Reti, 1958; Simms 1975, 119; Judd, 1998; Dahlhaus 1990). Although Fétis used it as a general term for a system of musical organization and spoke of types de tonalités rather than a single system, today the term is most often used to refer to Major-Minor tonality (also called diatonic tonality or functional tonality), the system of musical organization of the common practice period and most popular music in much of the world today.