Cavatina (f)
(with) definite article: ? [a / la?]internal canal of a tube; conical (tapered), or cylindrical
Internal canal of a tubes [or is this the term for the conical bore only?]; NOT to be confused with the Italian (and English) term for a "short song of simple character".
Bonanzinga, Sergio: La zampogna a chiave in Sicilia. In: La zampogna: gli aerofoni a sacco in Italia (2005), II, p.192.