Bourdon minuscule (m)
(with) definite article: lehigh drone, adjustable: details?
According to Chassaing, "... a third drone attached to, but not integrated in the main stock"; Montbel describes it (and its position), however, as "a tiny, and therefore very acute, third drone, discretely placed behind the Boîtier-tête; NB: ➺ homonyms, &c.
Chassaing, Jean-François: La tradition de cornemuse en Basse-Auvergne et Sud-Bourbonnais [Thèse de doctorat, ethnologie 3e cycle, Univ. Lyon 2, 1981]. Moulins, 1983 (© 1982), p.84 (no term).
Montbel, Eric: Les cornemuses du Massif Central: Autour de la cabrette. In: Ricros (et al.): La cabrette… (2017), p.128.