(Fr. choeurs, rangs; Ger. Chöre, Saitenchöre; It. cori).
The term by which ranks of strings on plucked instruments were known from the 16th century to the 18th. Thus one would speak of a ‘ten-course’ lute, meaning one with ten sets of strings. A course may consist of one, two or even three strings; the lute usually has the first course (and, from about 1650 onwards, the second course) single and the rest double, and citterns often have triple third and fourth courses.
Although most commonly tuned to the same note, the strings comprising a course may be an octave apart. This was certainly a feature of lutes in the 15th and 16th centuries, though no less an authority than John Dowland condemned it as ‘irregular to the rules of Musicke’. The reason for octave courses was almost certainly the unsatisfactory tone of gut strings in the lowest registers, which may tend to sound solid and heavy. Some of the missing upper harmonics are provided by the higher octave string, but it must be very carefully chosen if it is not to overpower the lower string, and should be at considerably lower tension. The need for octave courses disappeared in the 17th century, when overspun strings first appeared, though they continued to be used even after this date.
Generally speaking, paired or tripled courses were used on instruments with relatively low-tension strings. The thicker strings usual from the 19th century onwards were employed singly, though the modern mandolin still has four double courses.
IAN HARWOOD