This article develops a method for interpreting Béla Bartók's early tonal practice that supposes a conceptual shift from a relatively historically static major-minor tonality to a multivalent, “evolving” tonality in which works express individual variations on abstract, communal ideas of key. Starting with Edward Gollin's recent generalization of Moritz Hauptmann's key representations as “multiaggregate cycles”—which he also uncovers on the surface of and in the relations between harmonies in Bartók's music—the article briefly reconsiders Hauptmann's theories and depictions and then elaborates on the relation between those key depictions and multiaggregate cycles. Ultimately, it argues that augmented and diminished triads—the harmonies disjunctive to the alternating major and minor thirds that generate Hauptmann's representations—form the primary basis for Bartók's multiaggregate cycles and that these “(048) or (0369) chains” exemplify augmented and diminished tendencies propelling the development of new key variations. By way of demonstration, the article ends with several analyses of Bartók's works from the decade 1908–17: the first movement of the Second String Quartet (1914–17), “Three Autumn Teardrops” from the Five Songs, op. 16 (1916), the fourth of the Four Dirges (1910), and the Tenth Bagatelle (1908).