Appendix 2: pentatonicism and chromaticism
Although musical scales and pitch systems have no counterpart in the visual arts and are therefore strictly speaking irrelevant to this thesis, the pentatonic character of Gaelic music is one of its strongest features and can hardly be ignored when speaking about its structure. Irish music employs several pentatonic modes. The basis of all the old melodies is pentatonic, and many of the best tunes are completely pentatonic (example 17). The majority of good tunes, such as the two reels analysed above (The Drunken Landlady and Paddy Reynolds' Reel), are mostly pentatonic but use diatonic notes in passing. A number of good tunes will employ different pentatonic modes at different points. A few tunes contain small amounts of chromaticism, though in older versions of a melody, as opposed to more recent variants, this is always decorative, like the classical chromatic apoggiatura, rather than structural i.e. implying a harmonic modulation (example 18).
Modules form the foundation of each tune, and in the best tunes – that is to say those acknowledged as the best by traditional musicians – these are normally pentatonic.
Example 17: The Lady of the House and The Killarney Boys of Pleasure, two completely pentatonic reels. Traditional players will add many more gracings than the rolls shown.
Example 18 Irish chromaticism: the first strain of Tatter Jack Welsh
