Implications for octave chromaticism
A major innovation to the modal system for harpers is the application of chromaticism at the
octave, a technique particularly characteristic of Munster music and of larger vocal ranges.
One octave chromaticism is possibly described by Bunting in MS29 p157 inasmuch as it is a
single ff natural in a gamut otherwise occupied by F#s. It can be argued that there the device
operates to save retuning the harp from the leithghléas to téad leagaidh tuning for certain
melodies where only one ff natural is heard. Nevertheless, the feature does appear quite
widespreadly within Irish song, often in tandem with 'ficta'-like notes unavailable on the Gaelic
harp.
Like the 'G mode' structures somewhat extraneous to the three main slinneachan of the seòl
slinneadh, octave chromaticism could be added onto the seòl slinneadh as a standard device,
using an f#, and either a bb flat or c# string (depending on whether the harp were to be in the
one sharp or all naturals tuning). Bunting mentions the use of a cc# string which may have
been used to save retuning the harp out of one sharp tuning in order to set tunes which would
normally be in the key of D natural in the key of E one sharp . He may have illustrated the
note in the wrong octave however - or the precise octave may not have been relevant.
A rare example of the use of chromaticism at the octave in Scottish Gaelic song is Tha mo
ghruaidhean air preasadh, no.7 in Patrick MacDonald's Collection of Highland Vocal Airs. This
is a typical example of the lower seventh of the scale being raised in pitch while the upper
seventh is lowered. The other main application of this feature is to change the lower minor
third to the major.
Some octave chromaticism can be quite dramatic in nature, particularly that which, as in
musica ficta, is mobile within the confines of a melody. The Gaelic harp cannot switch to a
sharp note from a natural note in the middle of a song; however much Irish traditional song
does this, even with harp tunes.
To take an example, Dáithí Ó hÓgain's book Binneas thar Meon includes a Ring version of An
Draighneán Donn. For theoretical purposes, we can place the song final on the pitch c in the
slinn G. The pitch of the final occurs numerous tunes during the body of the tune. The singer
Pilib Ó Foghlú takes this normally very strong pitch and sharpens it in various places in the
body of the melody, making it seem as if the tune should really finish on d but actually finishing
oddly on c (oddly if you are unaccustomed to such practice).
When this chromaticism at the octave is removed, by the naturalisation of all the c pitches, the
can ear can relate the tune more recognisably to that of the song in the north of Ireland. Such
examples perhaps encourage us to question whether to unite the concept of mode so closely
with that of scale.