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
The equation above indicated 146 Hz and the Nielsen equation indicated 138 Hz. Clearly, the whistle was being driven by a cavity resonance. This is an example of a whistle being driven in edge tone fashion but the result is a monopole sound field.