Tin whistle
In recent years a number of instrument builders have started lines of "high-end," hand-made whistles, which can cost hundreds of dollars US each — expensive in comparison to cheap whistles, but nevertheless cheaper than most other instruments. These companies are typically either a single individual or a very small group of craftsmen who work closely together. The instruments are distinguished from the inexpensive whistles in that each whistle is individually manufactured and "voiced" by a skilled person rather than made in a factory.
Physics of whistles
This whistle has dozens of popular names. Pipes with sinusoidal variations of radius are often created to permit bending. Steady flow through the pipe at low Reynolds numbers results in a fluctuating volumetric flow rate that generates a monopole-like sound field at the pipe exit. Examples of such pipes are shown in figure on the right.