A systematic lack of a concise picture of the Istrian Scale outside its territory is mainly due to a unique cultural cross-section of Slovenian, Croatian, and Italian underpinnings. This paper follows the metamorphosis of the Istrian scale from its folkloric origins on the Istrian peninsula on the northeastern coast of the Adriatic Sea to its manifestation in modern classical compositions of Slovenian classical (art) music. Supported with samples of Istrian folk music, the research follows a succession of musicologists and their efforts to transform the folkloric idioms into a concise formula of a hexatonic tone row as well as the formation of the octatonic Istrian scale. The employment of this unique phenomenon in classical compositions is analyzed in piano pieces of Slovenian composers Karol Pahor and Danilo Švara.