Tin whistle of which tone holes the player should cover. The most common format is a vertical column of six circles, with holes to be covered for a given note shown filled with black, and a plus sign (+) at the top for notes in the second octave. Tablature is most commonly found in tutorial books for beginners. The tonic solfa is found in Ireland and possibly Wales, especially in schools. Many schools have printed sheets with tunes notated in tonic solfa, although in Ireland more have teaching by note. With the availability of good standard notation tutor books, teaching is possibly
Tin whistle "cross-fingering" (covering some holes while leaving some higher ones open). However, half-holing is somewhat more difficult to do correctly, and whistles are available in many keys, so for other keys a whistler will typically use a different whistle instead, reserving half-holing for accidentals. Some whistle designs allow a single fipple, or mouthpiece, to be used on differently keyed bodies. There are larger whistles, which by virtue of being longer and wider produce tones an octave (or in rare cases two octaves) lower. Whistles in this category are likely to be made of metal or plastic tubing, sometimes with a tuning-slide