Whistles may have a conical or cylindrical bore, and if well constructed, the shape of the bore has no impact on the sound of the instrument. The material and spacing of the tone holes have a bigger influence on the sound. Bore shape is simply a matter of personal preference.

Many whistles, such as the Sweetone, Oak and Generation whistles, have metal bodies and plastic mouthpieces. They can be tuned by breaking the glue seal and sliding the mouthpiece away from the body, thereby lowering the pitch. Those that are one-piece metal instruments, such as the Clarke Pennywhistle, cannot be tuned. Others may even be constructed with a tuning slide or a mouthpiece that slides easily along the upper portion of the body.

Each instrument requires a different amount of air and will respond differently with an individual. Plastic whistles tend to have a more mellow, almost recorder-like sound that may be preferred for indoor solo playing or for English country dance music. Metal whistles tend to be louder and are more suitable for sessions.

Whistles are diatonic instruments that play in the major key for which they are named, with the lowest note of the scale starting with all the tone holes covered. D whistles are the most common key chosen for Irish dance music. Cross fingerings allow for certain accidentals when other keys are desired, but there comes a point when it makes more sense to choose a whistle of a different key. As the keys get lower, the instrument gets bigger and the spacing between tone holes spreads further. The cutoff point between whistles and low whistles is generally accepted at the key of G or A. Low whistles tend to be made of all plastic or all metal.

When choosing any type of whistle, the most important factors are materials and the amount of care needed to maintain the instrument, the type of sound desired, the instrument's response with different amounts of air and whether or not it plays in tune throughout the range.

TABOR PIPE

Tabor pipes are also fipple flutes, but have only three holes and can therefore be played with one hand. It was used in medieval times with a tabor (type of drum) that was played with the musician's other hand. They are popular today for Renaissance music and Morris Dancing (English fold dance). Often made of plastic, such as those by Susato, are available in various keys and can be fairly loud. They may require a lot of air and breath control to hit the overtones. Brass tabor pipes are also common, as produced by Generation, and tend to have more of a shrill tone in comparison to the plastic Susato tabor pipes.