Wikipedia
Canntaireachd ( Scottish Gaelic: literally, "chanting"; ) is the ancient Scottish Highland method of notating Piobaireachd, also spelt Pibroch, referred to more generally as Ceol Mòr (literally the "big music"), an art music genre primarily played on the Great Highland Bagpipes. These long and complex theme and variation tunes were traditionally transmitted orally by a combination of definite vocable syllables. In general, the vowels represent the notes, and consonants the grace notes, but this is not always the case, as the system has inconsistencies and was not fully standardized.
Pipers have used musical staff notation to read and write pibroch tunes since the early nineteenth century. Many of the early staff notated scores for modern pibroch published by Angus MacKay and authorised by the Piobaireachd Society are now considered by scholars to have been oversimplified, with standardisations of time signatures and editing out of ornamental complexities, when tunes are compared with versions in earlier manuscripts such as the Campbell Canntaireachd. The practice of canntaireachd singing remains the preferred means for many pipers to convey the musicality and pacing of pibroch performance when teaching or rehearsing a tune.
Canntaireachd was first written down at the end of the 18th century in the Campbell Canntaireachd by Colin Cambell of Nether Lorn, Argyll. While his vocable system had its origins in chanted notation, the Campbell Canntaireachd is now considered to have been intended as a written documentation of the music, to be read rather than sung. Nevertheless, Cambell's Nether Lorn Canntaireachd was adopted by the Piobaireachd Society in their publications and has become the most commonly used vocable system. Another related system of Canntaireachd was published by Niel McLeod of Gesto, reputedly taken down from the chanted singing of John MacCrimmon, one of the last practicing members of that esteemed piping family. The MacArthur family of pipers are reported to have had their own oral form of Canntaireachd system that was not documented. A further variety of Canntaireachd and distinct collection of pibroch tunes was sourced from Simon Fraser, whose family emigrated to Melbourne in the 19th century. It is assumed that different lineages of pipers developed distinct forms of Canntaireachd that were variations on a broadly similar system of sung vocable notation. This informal oral variation continues today in the practices of experienced piping musicians and teachers.
William Donaldson, in The Highland Pipe and Scottish Society 1750-1950 states:
"In its written form, canntaireachd provided the basis of the indigenous notational system and it was brought to its most developed form by Colin Mór Campbell of Nether Lorn in Argyll, at the end of the 18th and the beginning of the 19th Century. Although Campbell's work was almost immediately superseded by a form of staff notation adapted specifically for the pipe, and remained unpublished and unrecognised until well into the 20th Century, it remains an important achievement and gives valuable insight into the musical organisation of Ceòl Mór"