The most common whistles today are made of brass tubing, or nickel plated brass tubing, with a plastic fipple (mouthpiece). Generation, Feadog, Oak, Acorn, Soodlum's (now Walton's), and other brands fall in this category. The next most common form is the conical sheet metal whistle with a wooden stop in the wide end to form the fipple, the Clarke's brand being the most prevalent. Other less common variants are the all-metal whistle, the PVC whistle, the Flanna square holed whistle, and the wooden whistle.

Whistles are a prevalent starting instrument in Irish traditional music, since they are often cheap , relatively easy to start with (no tricky embouchure such as found with the flute), and the fingerings are nearly identical to those on the traditional six holed flute (Irish flute, baroque flute). The tin whistle is the most popular instrument in Irish traditional music today.

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. It is common for builders of wooden flutes and Uilleann pipes to also build whistles. 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.