At the end of Close Encounters of the 3rd kind, the French guy does a hand symbol that the alien repeats. The symbol is a fist, a flat hand and then a flat hand vertical. Is there any reason they picked those 3? I ask because I just had a Dr. ask me to do those 3 symbols/gestures to test me.
Those are the Curwen solfege hand signs. Each sign corresponds to a note on the musical scale. The Close Encounters notes are: Re, Mi, Do, Do, Sol (the second Do is an octave lower than the first). So you do:
Raised open hand
Flat open hand
Fist
Lower Fist
Perpendicular open hand
You, too, can communicate with aliens!