The piccolo is a small flute. Like the flute, the piccolo is normally pitched in the key of C, one octave above the concert flute. Music for the piccolo is written one octave lower than concert pitch. Fingerings on the piccolo correspond to those of the flute, but sound an octave higher as the piccolo is considerably less than half the size of the flute. Also, many alternate fingerings may be used to tune the individual pitches, as many are consistently out of tune. In addition to the standard C piccolo, there is a piccolo pitched in D♭ that is sometimes used in bands, and one in A♭, rarely used outside Italian marching bands.
It is mainly used in orchestral pieces but there are a few pieces specifically for it. Often in orchestras, the piccolo player doubles up as a second or third flute because not all orchestral pieces include piccolo parts.
Because the piccolo's sound is in a very high register, it has a potential to be strident or shrill. Thus, it is often used only as an ornamental, "flavor" or "garnish" instrument, or not at all. Nonetheless, there have been many concertos and solo pieces written for the piccolo, written by notable composers such as Persichetti, Vivaldi, and Todd Goodman. (Vivaldi’s concertos, however, were originally for the sopranino recorder). Triple-woodwind orchestral works typically include two flutes and one piccolo or three flutes with a piccolo double. Not all flute players play piccolo, although most professional players do. Though the fingerings are the same, the embouchure and other differences do require a separate effort to learn. Also, flute players with large fingers may find it difficult to press the smaller piccolo keys accurately.
The piccolo can be quite noticeable in concert marches. For example, John Philip Sousa's "Stars and Stripes Forever" carries a piccolo solo.
It is increasingly difficult to sustain notes in the third octave, especially softly.
The piccolo is somewhat notorious for being difficult to play in tune, as evidenced by the jokes circulating among musicians that defines a minor second as “two piccolos playing in unison,” or that the only way to get two piccolos to play in tune is to "shoot one of them". Its small size makes it difficult to construct completely in tune and causes what would be small pitch variances in larger instruments to become rather significant. The fact that it is so high does not help as it is rather conspicuous when out of tune.
Piccolos may be constructed out of wood, metal, gold, plastic, or a combination of all of them. Many piccolo players find that wooden piccolos offer a more mellow timbre than metal ones. A popular compromise combines a metal head joint with a body made from wood. In more recent years the piccolo has also been made out of a plastic composite material. The composite piccolo is durable enough for marching and produces a fair quality sound. Most professionals agree that a piccolo should be made out of only one material, as two separate materials with different coefficients of thermal expansion lead to tuning inconsistencies.