Monochord.jpg Pneumatic organ, fourth centuryThumbnailsLute, ElizabethanPneumatic organ, fourth centuryThumbnailsLute, Elizabethan

The monochord was mounted with a single string stretched over two bridges which were fixed on an oblong box. The string could be tightened or slackened by means of a turning screw inserted into one end of the box. The intervals of the scale were marked on the side, and were regulated by a sort of movable bridge placed beneath the string when required. As might be expected, the monochord was chiefly used by theorists; for any musical performance it was but little suitable. About a thousand years ago when this monochord was in use the musical scale was diatonic, with the exception of the interval of the seventh, which was chromatic inasmuch as both b-flat and b-natural formed part of the scale. The notation on the preceding page exhibits the compass as well as the order of intervals adhered to about the tenth century.

Musical Instruments
Written by Carl Engel
Published in 1875
Available from gutenberg.org