About KotoViewer

KotoViewer is a program that displays music scores in koto notation (Ikuta School) or shamisen (sangen) notation. Although most of the conversion is done automatically, users can control the process through a procedure called score annotation.

KotoViewer reads Western-music notation scores in MusicXML format, for instance created by MuseScore. An example of such a score, Sakura Sakura, is shown below as displayed in MuseScore and KotoViewer. Another example screenshot shows the first page of the piece called Haru no umi (Spring Sea). The Pitch Analysis Dialog, which assists users for koto tuning decisions, is also presented.

Sakura Sakura
(Western notation score)
Sakura Sakura
(koto score)
Sakura Sakura
(sangen score)
Haru no umi
(koto score)
Pitch Analysis Dialog


  • Supports notation for 13-string and 17-string koto instruments and shamisen (sangen)
  • Allows specifying the initial tuning via standard names (Hira, etc.) or per-string tuning, and also mid-way tuning changes
  • Displays various Western music notations: tempo, dynamics, repeats, arpeggio, grace notes, trill, glissando, etc.
  • Supports input in compressed and uncompressed MusicXML formats
  • Facilitates score display through a MuseScore plugin
  • Allows configuring the language of the user interface in English or Japanese
  • Includes a detailed User Guide in English and Quick Reference Guide in Japanese

What's new in v0.3.1

  • Added support for multi-measure rest display
  • Updated koto notation fonts to use more realistic characters
  • Added support for natural scale tuning in pitch analysis dialog
  • Added support for displaying trill and glissando notation
  • Improved display for time signatures with eighth note beats (6/8, etc.)
  • Updated the plugin to support MuseScore 2
  • Added a Quick Reference Guide in Japanese
  • Various bug fixes and other minor improvements


MuseScore plugin

MuseScore is is a free music composition and notation software, which can be used not only to input music notation, but also to import other file formats such as MIDI or even PDF. To make it easier to use KotoViewer, I created a MuseScore plugin, so that the currently opened score in MuseScore can be displayed in KotoViewer without any other actions required from the user. For more information, check the plugin page on the MuseScore website.