Fipple

The accompanying illustration of the mouthpiece of a recorder shows a wooden block (A) with a channel carved into the body of the instrument (B), together forming a duct that directs a ribbon of air across an opening toward a sharp edge (C).

… Some kinds of winde-instruments, are blowne at a small hole in the side, which straitneth the breath at the first entrance, the rather in respect of their traverse, and stop above the hole, which performeth the fipples part, as is seene in flutes and fifes, which will not give a sound by a blast at the end, as recorders &c., doe.By this description, the fipple is a plug that nearly closes one end of the pipe, open only for the duct that "straightens” the channel of air blown axially into the instrument.

Subsequent authors have used the term in that sense but differ in the element of the mechanical aggregate illustrated above that they regard specifically as the fipple.

This ambiguity is detailed in the article headed Fipple in Grove Music Online, which concludes, "Since nobody can agree what the term means, to avoid further confusion its use should be abandoned.

One example of this is the set of finger holes that laterally pierce the body of a recorder and are opened or closed to change the length of the vibrating air column.

This passage is alternately termed a windway and ends at an opening referred to as a window, bounded by the edge on the opposite side.

Duct flutes have a long history: an example of an Iron Age specimen, made from a sheep bone, exists in Leeds City Museum.