The ancient ou was constructed with only six tones which were attuned thus—f, g, a, c, d, f. The instrument appears to have become deteriorated in the course of time; for, although it has gradually acquired as many as twenty-seven pieces of metal, it evidently serves at the present day more for the production of rhythmical noise than for the execution of any melody. The modern ou is made of a species of wood called kieou or tsieou: and the tiger rests generally on a hollow wooden pedestal about three feet six inches long, which serves as a sound-board.