The Hydrocrystallophone is a novel music instrument invented by Attoparsec. Also called the Glissando, or Gliss, or the Mechanical Theramin, it is a new take on the old glass harp or glass armonica.

Instead of offering multiple glasses tuned to different frequencies, it provides a single rotating glass. The tone this glass produces can be changed by means of the pipe which extends into it. This is attached to a pump cylinder, which can add or remove water as the glass is played.

Glass rotation is achieved by means of a 1920s phonograph motor which was restored for this purpose. Future plans include modifying the motor governor to reduce the speed in order to reduce unnecessary centrifugal effects on the water.