The glockenspiel is a series of bars arranged according to tone that produce a series of "rings" when hit. Like a xylophone, the glockenspiel is played with two hammers, but it is played vertically and is small enough to be carried by members of marching bands.
The glockenspiel produces sound when percussion occurs. The length of each bar determines the note it will make. Longer bars produce larger reverberations when hit thus producing a deeper tone.
Hear a glockenspiel