The gestures behind shalshelet ("chain") is (to my knowledge) the one gesture that is described by the Diqduqê ha-Te`amim. The gesture involves the waving of the hand sideways, apparently with the four fingers slightly parted. Such a gesture aptly illustrates a descent of a major or minor third from the sustained note, then a rise via a chain of chromatic intervals back to the sustained note. The written sign is found in both the prosodic system (rarely) and in the psalmodic system (less rarely).

Updated December 27, 2011