XYLOPHONE (Fr. xylophone; Ger. Xylophon, Strohfiedel or Holzharmonika; Ital. armonica de legno)  , a small instrument of percussion, of definite sonorousness, used in the orchestra to mark the rhythm . The xylophone consists of a series of little wooden staves in the form of a half cylinder and graduated in size . The staves, each of which represents a semitone,est on two, three or four wooden bars, covered with straw and converging to form an acute angle . They are so arranged that each stave is isolated . In some models the staves are grouped in two rows, comprising the naturals and the accidentals . The xylophone is played with two little wooden hammers, and has a compass of two or three octaves . The quality of tone is inferior to that of the steel harmonica or glockenspiel . (K .