Internal canal of a tube; Conical (or tapered), with a diameter that is downwards increasing (as usual in chanters of western bagpipes) or decreasing (as in Recorders and Penny whistles); Cylindrical: from top to bottom an even diameter.

Technical qualities: ➺ Conical & Cylindrical; NB: ➺ "Telescope-like".

Conical (bore), Cylindrical (bore)