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 narrowing the lip/embouchure. Since the size and direction of the tin whistle's windway is fixed, like that of the recorder or fipple flute, it is necessary to increase the velocity of the air stream. (See overblowing). Fingering in the second register is generally the same as in the first/fundamental, though alternate fingerings are sometimes employed in the higher end of the registers to correct a flattening effect caused by higher aircolumn velocity. Also, the tonic note of the second register is usually played with the top hole of the whistle partially uncovered instead of covering all holes as with the