A bell tree (often confused with the mark tree) is a percussion instrument, consisting of vertically nested inverted metal bowls. The bowls, placed on a vertical rod, are arranged roughly in order of pitch. The number of bowls can vary between approximately 14 and 28. An effective glissando is produced by sliding a triangle beater, a glockenspielmallet, or a xylophone mallet down the length of the tree. When a glissando is played, the inexactness of the order of the bowls' pitch is unnoticeable, merely creating a fuller sound.
The bell tree is often used to accentuate the start or end of passages of music with a "bright", "shimmer" effect, adding complexity.