The Tuʻungafasi or Tongan music notation is a subset of the standard music notation, originally developed by the missionary James Egan Moulton in the 19th century for singing church hymns in Tonga.
Tongan music from the pre-European times was not really music in the current sense but rather a non tonic recital (like the 'pater noster'), a style still known nowadays as the tau fakaniua. Therefore, when the missionaries started to teach singing, they had also to start with music from scratch. They found the doh-ray-mi-fah-sol-la-si-doh scale sufficient for their needs, avoiding the very complex and difficult to learn international music notation. But due to the limited number of consonants in the Tongan language, the note names were localised into to-le-mi… Unfortunately the word 'tole' is a vulgar expression for the Female genital area, and as such not to be used.
Moulton then developed a system where the main notes were indicated with the numbers 3 to 9, while a strike to the digits was used to sharpen them, for example: 7, being 7# or 8b. At the end the full 12 notes of the octave became: 3-3-4-4-5-6-6-7-7-8-8-9, which are pronounced as: to-lu-fa-ma-ni-o-no-tu-fi-va-a-hi, (variants of the Tongan numerals 3 to 9 being tolu, fā, nima, ono, fitu, valu, hiva). To extend the single octave (MIDI octave number 4) into the next higher, a dot can be put above the number. To reach the next lower, a dot or a little tail can be put under them. If needed 2 tails can be taken to arrive at even lower pitches, but that is rare. Since the notation is made for human singing, it does not need to have the extended range of musical instruments.
The Moulton notation, or Tongan notation was extremely popular and is still cherished by the Tongans. It is extremely common to see bandmasters writing out the music on the blackboards in the church halls during choir practices.
Tongan singers recognise up to 4 voices, which results in the typical 4 lines of numbers in the notation. The leading voice is called 'fasi', a male voice. The next one is kānokano or alto, a female voice. The third is the tēnoa or tenor, and the last one the laulalo or bass. Occasionally the bass sings different lyrics from the rest. The middle octave (of the 3 octave range mentioned above) varies with the voice, the kānokano is usually one above the tēnoa, while the laulalo is one below. In addition the exact position of the middle doh or C depends on the key signature as in this schedule: