This dissertation serves as an analysis and performance guide for No-Re I for Flute Solo (2018) by Gyu-Bong Yi (이규봉), a work that combines Korean elements and Western compositional techniques. The modern flute, developed in the mid-nineteenth century with the Boehm's Schema, has pushed the boundaries of the instrument through experimentation with new techniques, leading to numerous contemporary works presenting unique challenges for flutists. No-Re I includes passages with various extended techniques and unique combinations, requiring specific solutions to overcome the challenges they present. For example, this dissertation offers specific fingering diagrams and descriptions for executing the double trills used in No-Re I. Additionally, certain notations used by the composer may have limitations in projection or clarity, and this dissertation elucidates the composer's intent based on an interview and provides solutions for these limitations. This research also discusses the fusion of Korean and other East-Asian aesthetics with Western musical language including the works of Isang Yun (1917–1995), a Korean-born musical pioneer, who had a successful career as a composer and educator, especially elaborating on his unique compositional technique, the Haupttöne, which is based on tonal centers influenced by East-Asian philosophy, Korean folk music, and its unique characteristic of ornamenting the main tone.