The cittern is one of the few metal-strung instruments known from the Renaissance period. It generally has four courses (single, pairs or threes) of strings, one or more course being usually tuned in octaves, though instruments with more or fewer courses were made. The cittern may have a range of only an octave between its lowest and highest strings and employs a re-entrant tuning  – a tuning in which the string that is physically uppermost is not the lowest, as is also the case with the five-string banjo and most ukuleles for example. The tuning and narrow range allow the player a number of simple chord shapes useful for both simple song accompaniment and dances, however much more complex music was written for it.  Its bright and cheerful timbre make it a valuable counterpoint to gut-strung instruments. The Spanish bandurria , still used today, is a similar instrument.
It is a strange thing to observe, how high a rate great kings and monarchs do set upon this fruit of friendship, whereof we speak: so great, as they purchase it, many times, at the hazard of their own safety and greatness. For princes, in regard of the distance of their fortune from that of their subjects and servants, cannot gather this fruit, except (to make themselves capable thereof) they raise some persons to be, as it were, companions and almost equals to themselves, which many times sorteth to inconvenience. The modern languages give unto such persons the name of favorites, or privadoes .... And we see plainly that this hath been done, not by weak and passionate princes only, but by the wisest and most politic that ever reigned; who have oftentimes joined to themselves some of their servants; whom both themselves have called friends, and allowed other likewise to call them in the same manner; using the word which is received between private men.