Umulsai: A Plain-Text Format and In-Browser Engraving System for Jeongganbo, Korean Mensural Notation
2026-07-27 • Digital Libraries
Digital Libraries
AI summaryⓘ
The authors describe Umulsai, a new web-based editor designed to write Jeongganbo, a traditional Korean music notation system from the 15th century. Since Jeongganbo uses a grid of beat-cells read right to left, it doesn't work well with tools made for Western music notation. Umulsai allows users to edit Jeongganbo in a simple text format that matches the grid layout and automatically handles its unique visual rules. The authors also explain how their tool can produce high-quality printed scores, play back music, and work with other music data formats. They built and tested this tool with AI help and compared it against official Jeongganbo examples to make sure it works correctly.
Jeongganbomensural notationKorean traditional musicengravingbeat-cellsgrid notationmusic editorMusicXMLMEIoptical music recognition
Authors
Danbinaerin Han
Abstract
Jeongganbo is a grid-based mensural notation created in fifteenth-century Korea and still in standard use for Korean traditional music. Its structure -- a vertical column of square beat-cells read right to left, in which the position and share of a syllable inside a cell encode its duration -- is incompatible with engraving systems built for Western staff notation, and no practical digital tool for producing it has been in sustained distribution. This report describes the technical design of Umulsai, a jeongganbo editor that runs entirely in a web browser as a static, serverless application. Its core is (i) a human-writable plain-text format whose spatial arrangement corresponds one-to-one with the notational grid, so that duration is expressed by position and share in the text exactly as on the page; (ii) an engraving engine that formalizes the typesetting conventions of published scores -- right-to-left column flow, daegang section lines, octave-variant Sinographs, ornament attachment and micro-spacing -- as automatic rules; and (iii) a dependency-free implementation in which documents remain plain data, enabling print-quality output, playback, and interchange with recently proposed machine-oriented encodings of jeongganbo. We specify the format and its rhythmic semantics, describe the engraving model and its typographic edge cases, and discuss limitations and planned interoperability with MusicXML/MEI and optical music recognition pipelines. The implementation was produced through an AI-assisted workflow led by a domain expert and verified behaviorally against published reference scores; this workflow and its verification regime are disclosed in the report.