Both theories find part of their inspiration in the theories of Jean-Philippe Rameau, starting with his "Traité d'harmonie" of 1722. Even if the concept of harmonic function was not so named before 1893, it could be shown to exist, explicitly or implicitly, in many theories of harmony before that date. Early usages of the term in music (not necessarily in the sense implied here, or only vaguely so) include those by Fétis ("Traité complet de la théorie et de la pratique de l'harmonie", 1844), Durutte ("Esthétique musicale", 1855), Loquin ("Notions élémentaires d'harmonie moderne", 1862), etc.