Disco ball

Miniature glitter balls are sold as novelties and used for several decorative purposes, including dangling from the rear-view mirror of an automobile or Christmas tree ornaments.

[2][3] An early example can be seen in the nightclub sequence of Berlin: Die Sinfonie der Großstadt, a German silent film from 1927.

From the 1960s to the 1980s, these devices were a standard piece of equipment in discothèques, and by the turn of the millennium, the name "disco ball" had grown quite popular.

The film includes several sequences where glittery reflections from a disco ball fill San Francisco's Winterland Ballroom during a series of 1974 performances.

"A twirling mirror ball overhead also adds some visual flash to the image," notes a reviewer.

During The Girlie Show in 1993, she descended while sitting on one before performing "Express Yourself", and later in 2006, she used a 2-ton glitter ball that was embellished by 2 million dollars worth of Swarovski crystals, which used a hydraulic system to open like flower petals for her entrance during her Confessions Tour.