1. Why Braille Music Is Written on One Line While Staff Notation Uses Two Dimensions
Staff notation is a two-dimensional system: vertical position shows pitch, and horizontal arrangement shows the flow of time. However, Braille can only be read by running fingers across it horizontally. Therefore, in Braille music, both vertical information (pitch) and horizontal information (time) are lined up in a single row [1].
The basic idea is to translate all notes and symbols from the staff into Braille, arranged in the order the music progresses [2]. Symbols for dynamics (loudness) and tempo (speed) also go in this same line, so one measure of music can take up several lines of Braille [1].
There are rules for where symbols go. According to Wikipedia, symbols for dynamics, tempo, and octave signs are placed before the notes, while dots and slurs are placed after the notes [2]. This means the reader can simply move their fingers from the beginning and encounter all the necessary information in order. Next, we look at how information is written within a single cell.
2. How Braille Music Splits the 6 Dots of a Cell into a Top 4 and a Bottom 2
In Braille music, the 6 dots in one cell are divided. The top 4 dots (positions 1, 2, 4, and 5) represent the pitch (do, re, mi, etc.) and rests. The bottom 2 dots (positions 3 and 6) represent the length of the note [2]. This means two pieces of information—height and length—fit into the same single cell.
The length is determined by whether the bottom dots are present. If neither dot is present, it is an eighth note. If only dot 6 is present, it is a quarter note. If only dot 3 is present, it is a half note. If both dot 3 and dot 6 are present, it is a whole note [1].
Here is a problem. There are only four possible combinations for the bottom dots to show length. Because of this, the shape with both dot 3 and dot 6 represents not just a whole note, but also a sixteenth note [1]. So, notes that are 16 times different in length have the exact same shape. How do readers tell them apart?
3. How Empty Spaces at Bar Lines Help Tell Whole Notes from Sixteenth Notes
The clue is the blank cell marking each bar line. In Braille music, a bar line is represented by an empty space of one cell. It is explained that if there is an empty space (the blank cell between measures) on both sides, and only one shape is between them, it can be identified as a whole note. If multiple shapes of the same kind are lined up within a measure, it is a clue that they are sixteenth notes [1]. In practice, readers also use the length of the measure and the flow of the music to decide.
This means the dots themselves do not distinguish the notes; the relationship with the surrounding spaces does. Since Braille has only 64 possible combinations, one shape is given multiple meanings, and its role changes depending on where it is placed [4].
It is explained that this ambiguity is rarely a problem in real music. It is uncommon for very long and very short notes to be adjacent. The style of the song and the length of the measure make it easy to guess which note it is [2].
While there are only four shapes for length, the top 4 dots for pitch can also only represent one octave.
4. How Octave Signs Decide Pitch When the Top 4 Dots Cover Only One Octave
The top 4 dots can only represent one octave, from do to si. Therefore, in Braille music, an octave sign is placed immediately before the note to decide which octave the note is in [2][3].
Because the pitch is decided by this symbol, Braille music does not usually use clefs like the treble clef found in staff notation [2]. However, clefs are sometimes used to distinguish the right hand from the left hand when playing the piano [2].
If the direction of the melody is clear from the flow of the music, such as when moving to a nearby note, this octave sign can be omitted [2]. The reader memorizes the notes one by one, using the pitch reference as a guide while moving their fingers.
Thus, height, length, and measure breaks are all written using only 6 dots and empty spaces. The person who built the foundation for this system was Louis Braille.
5. Louis Braille, Inventor of Braille Music, Was Also an Organist
Louis Braille invented Braille music notation [3]. In a book he published in 1829, he showed methods for writing words, music, and simple songs using dots [1].
Louis Braille himself was also an organist [1]. The system that makes music readable by touch and the fact that he was a performer are presented as separate facts.
Braille believed that if music could be written in Braille, the world of music would expand greatly [3]. The Braille notation for do-re-mi is still used worldwide today [3].
Yusuke Anazawa, a blind violinist interviewed by ONTOMO, says that the structure of Braille for the Japanese alphabet and the structure for do-re-mi are similar. This is because the Japanese alphabet Braille is built using combinations of dots for vowels and consonants [1].
6. Try Writing One Measure of Music as a Single Line, Like Braille Music
Choose one measure from a music textbook or sheet music at home. Write out the notes and symbols in that measure in order from left to right on a single line of paper. For example, write them as "C quarter, C quarter, G quarter," listing the note name and length.
If there are dynamic symbols, try placing them before the notes, following the rules of Braille music notation. By rearranging what was stacked vertically into a single horizontal line, you can experience part of what Braille music readers do.
If you want to know more, reading "What is Braille Music?" from the Braille Music Users Association will show you what Braille music looks like in Japan [3].