ENIn the chapter Rima Povilionienė examines Lithuanian microtonal music in a wider international context. At the beginning of the twentieth century, increasing attempts to produce microtonal music resulted as a response to the rapid changes taking place in the world and a burst of technological innovation. Microtonal experiments prompted the decline and transformation of the 12-tone temperament, introducing such theoretical ideas as el sonido trece (Carrillo) and sixth-tones scale (Busoni), bichromatic music (Möllendorff) as well as the rich and refined oeuvres of Wyschnegradsky, Hába, their pupils, and other followers. However, today the description of non-12-tone as well as music of different tuning, including microtonal, is rife with concepts and systematization attempts due to the variety of microtone applications and the highly individualized technological as well as aesthetic approaches by each composer. The chapter collects and examines the cases of microtonality systematization (e.g. bipartite generalization based on observations by Werntz, Denyer, Haas, etc.) in order to highlight the important features of microtonal music composition and to present specific cases in Lithuanian contemporary music that focus on operating with microtones as an expansion of the single tone (unison), shaping the glissando, manifestation of integral microchromatics (cf. ultrachromatics by Wyschnegradsky), and others. [From the publication p. 323]