Conical (bore)
internal diameter, increasing or decreasing downwards (i.e. counting from the stock)
Conique (Perce ~); Konisch (i.e. Konische Bohrung); Cónica (Sección ~).
Identical types: 4Conical pipes have a full range of overtones and can be overblown; They always sound 1 octave higher than a cylindrical pipe of the same length.
Meer, John Henry van der: Typologie der Sackpfeife. In: Anz. Germ. Nationalmus. (Nürnberg, 1964), p.124.