Nam June Paik(1932–2006), who earned a reputation for his ‘Action Music’ from the beginning of his career, called his music ‘Amusic’ while challenging himself to create unnamable music. He used everyday sounds(noises), actions, and audience participation, which have conventionally been regarded as ‘outside’ of music, his performances, and declared that he “exhibit[ed] music.” This study analyzes his early text score, SinfoNiE FoR 20 Rooms (1961), as a groundbreaking work reflecting his view of art. Paik emphasized variability and randomness, influenced by Cage’s chance operations and indeterminacy. This score, dominated by a recording tape collage, depicts 16 rooms, the synesthetic installation. ‘Space-music,’ a term Paik coined, nullifies the border between hearing and vision, and between audience, composer, and performer. It forms the intertwined chiasma of Parergon and Ergon. Naturally, this work, which attempts to be open form, requires an interdisciplinary reading. Although the work, a one-page text score, remained unperformed in Paik’s lifetime, it contains the concepts that predicted his future art. It is the turning point of Paik’s art itself, and the art of the threshold that contains the thought to come.