The xylophone is a percussion instrument with wooden bars of different lengths, arranged in the manner of a piano keyboard, with one row of black notes for the sharps and flats, and one row of white (or black)  notes for the scale of C major. In the picture here, all the keys are black.  The keys are struck with wooden beaters. The version used in the percussion section of a modern symphony orchestra also has a set of metal tubes or resonators suspended beneath the bars, thereby amplifying the sound produced.

The range can extend to 3 octaves starting from middle C.