Tin whistle all the holes closed, the whistle generates its lowest note, the tonic of a major scale. Successively opening holes from the bottom upward produces the rest of the notes of the scale in sequence: with the lowest hole open it generates the second, with the lowest two holes open, it produces the third and so on. With all six holes open, it produces the seventh. As with a number of woodwind instruments, the tin whistle's second and higher registers are achieved by increasing the air velocity into the ducted flue windway. On a transverse flute this is generally done by
Tin whistle 20th century, and also featured a brass tube with a lead fipple plug. The design was updated somewhat over the years, most notably the substitution of a plastic fipple for the lead plug design. While whistles have most often been produced in higher pitches, the "low" whistle is not unknown historically. The Museum of Fine Arts, Boston has in its collection an example of a 19th-century low whistle from the Galpin collection. During the 1960s revival of traditional Irish music the low whistle was "recreated" by Bernard Overton at the request of Finbar Furey. The most common whistles today are