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
Whistle post Whistle post A whistle post (or whistle board), in railroad usage, is a sign marking a location where a locomotive engineer is required to sound the horn or whistle. In Czech Republic, a whistle post is a red and white striped pole of different sizes and shapes and it's called "Pískejte" ("whistle"). In France, a whistle board comprises a black rectangular board bearing a white letter 'S' for ""Sifflez"" (= "whistle"). An additional white board with a black 'J' for ""Jour"" (= "day") indicates that the sign does not apply at night time. In Germany, a rectangular board bearing the