The shape of a cittern is more like that of a modern banjo than that of a lute, with a body near circular in outline and a relatively long neck, but, like a lute, is constructed entirely of wood. However, it is a wire-strung instrument like the banjo, and unlike the lute. Because of its strings it has metal frets, which are set into the fingerboard like those of a modern guitar. The vibrating string length of the instrument pictured is 43 cm, and its total length is 72.5 cm. The back of the instrument is flat. The sides of the body may be vertical, or slightly tapered, so the back is smaller than the soundboard. The sides are not of constant height, but shallower near the bottom of the instrument and taller near the point where the neck joins the body. This results in a somewhat wedge-shaped profile, as can be seen in the photograph below. Most citterns had between four and six courses, but instruments with as many as twelve courses are described in seventeenth century treatises. Citterns were generally double strung; that is, they were made with two strings for each pitch like most lutes or the modern mandolin, until some time in the eighteenth century. The bridge is not glued to the soundboard but is moveable and held in place by the pressure of the strings, which are fastened at the bottom of the instrument and pass over the bridge. Both of these design features are present in the banjo as well.
During the late sixteenth century and early seventeenth, citterns were made in a number of different sizes. Tenor and bass instruments were larger than the most common size pictured above. In the Italian states near the end of the sixteenth century, the bass cittern was called a ceterone and typically had a larger number of courses. On these instruments some of the lowest bass strings might be strung to a second pegbox on an extension of the neck, a design much like that of the theorbo or chitarrone.
Although the cittern seems to have developed in the Italian peninsula during the fifteenth century, it was particularly favored by the English from Elizabethan times through the seventeenth and eighteenth centuries. It was less popular in France and German-speaking areas, and in the Italian states after the mid sixteenth century the corresponding role was sometimes played by the mandolino. In the Iberian peninsula, the guitar would have been used instead.
The cittern had a long life as an actively-played instrument, and was used over a wide geographical area, resulting in an evolution of the design and variation in tuning in different contexts. In England, during the sixteenth and seventeenth centuries, they were most commonly strung with four courses of unison pairs. French and Flemish instruments also had four courses, but the lower two courses were were often triple strung, with one lower-pitch string and two at the upper octave. Italian citterns of the sixteenth and seventeenth centuries generally had six courses, with a mixture of single and double stringing.
Only about thirty citterns and one ceterone made in the sixteenth–seventeenth century are known to have survived. The vibrating string length of the citterns varies from about 38 cm to 62 cm, with the larger instruments being considered tenor citterns. The ceterone has two pegboxes and string lengths of 68 and 123 cm. No fifteenth-century instruments are known to have survived.
There were dozens of collections of music for the cittern published during the sixteenth, seventeenth, and eighteenth centuries, containing mostly secular music presented as vocal solos with accompaniment, as well as purely instrumental music. The level of complexity, sophistication and technical difficulty varies widely. Before the early seventeenth century the cittern was generally played by professional musicians. By the mid seventeenth century it had come to be thought of as an instrument for amateurs. The early playing technique is similar to that of a lute. During the sixteenth and early seventeenth centuries, music published for the cittern was set in tablature and clearly indicates that the strings are to be plucked with the fingers. Later, the plectrum became more common for playing simple chords.