Gallu (m)
(with) definite article: elodd sounds, result of imperfect technique (e.g. excessive pressure on the bag), &c.
Unpleasant sounding tone(s), resulting from excessive pressure on the bag, and usually going hand in hand with the instrument being out of tune.
La gaita asturiana: método para su aprendizaje. Oviedo, s.a. [1991], p.253.