The element in a phonograph cartridge that rides in the groove of a record. It consists of a small arm called the cantilever and the stylus tip. They are designed to be able to move in to orthogonal directions at once. (Orthogonal refers to two [or more] phenomena that can exist in the same medium at the same time and not interfere with one another. The vertical and horizontal motion of a properly working stylus tracking a record groove is an example of orthogonal motion.) Over the years many different shapes and materials have been tried with varied results, and of course, like most things audio, there is little agreement about what the ‘best’ system is.