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 tonic note of the first register; this makes it harder to accidentally drop into the first register and helps to correct pitch. Recorders perform this by "pinching" open the dorsal thumb hole. Various other notes (relatively flat or sharp with respect to those of the major scale) can be accessed by "cross fingering" techniques, and all the notes (except the lowest of each octave/register) can be flattened by "half holing". Perhaps the most effective and most used cross fingering is that which produces a flattened form of the seventh note (B instead of B on a C whistle, for example,