Pibroch - Structure

Structure

Related Ceòl Mór genres were historically also played on the fiddle and on the wire-strung Gaelic harp or clarsach. The clarsach Ceòl Mór is likely to have predated and influenced the later pipe and fiddle music. However, pibroch in its current form was developed on the Great Highland Bagpipe, with most of the extant pibroch tunes being adapted to or written specifically for the GHB, and as a result the musical form is influenced by features and limitations of that instrument.

In musical structure, pibroch is a theme with variations. The theme is usually a very simple melody, though few if any pibroch contain the theme in its simplest form. The theme is first stated in a slow movement called the ground or in Gaelic the ùrlar. This is usually a fairly stylised version of the theme, and usually includes numerous added embellishments and connecting notes.

The subsequent variations can number from one up to about twenty, although there are a few fragmentary tunes for which only a ground is known. In most cases the variations following the ground involve the use of a number of different musical embellishments, usually starting very simply and progressing through successively more complex movements before returning again to the ground.

Variations after the ùrlar or ground usually include a siubhal ("passing" or "traversing") or dithis ("two" or "a pair") or both. The siubhal comprises theme notes each coupled with a single note of higher or lower pitch that usually precedes the theme note. The theme note is held and its paired single note cut. The timing given to the theme notes is of critical importance in displaying the virtuosity of the master piper. If the theme and single note are repeated or played in pairs, it is referred to as a doubling, otherwise a siubhal singling.

The dithis is similar. The theme note is accented and followed by a cut note of lower pitch, usually alternating, for example, between an A and a G. If the coupled pairs are played in a repeating pattern, it too is called a dithis doubling.

Following the siubhal or dithis variation are other more complex embellishments. The Gaelic names of these type movements are: leumluath, taorluath, and crùnluath. In almost all pibroch in which these later movements are found, the variations are played first as a singling and then as a doubling and with a slightly increased tempo. However, not all pibrochs will include all or even any of these movements but instead use variations that are deemed to be irregular.

In addition the theme will usually have one of several internal structures for the ordering of its musical phrases. These are usually classified as follows:

• Primary - The theme or ground is composed of two two-bar phrases, A and B, played in the following order:
  • AAB
  • ABB
  • AB
• Secondary - The theme or ground is composed of four phrases, with A and B being one-bar phrases and C and D being two-bar phrases, and played in the following order:
  • ABCD
  • CBAD
  • CD
• Tertiary - A relative of Primary Pibroch, with three two-bar phrases, A, B, and C, played in the following order:
  • AB
  • ABB
  • AB
  • C
• Irregular - The theme or ground does not fit into any of the above structures.

Few pibrochs are pure examples of any of these structures though most can be fit into one of the first three with a slight modification of one or two of the phrases in one or more lines.

A compilation of the structure of many pibroch tunes, including related historical essays, was written by A. J. Haddow.

There is evidence from early treatises (e.g. Joseph MacDonald) that the structure was originally counted in 4, so a Primary form would be

• AABA
• BBAB

Similarly, Secondary form can be read as

• abABA
• baBAB