3-Tone Whistle
A whistle commonly used on and near Evergreen St. in Tucson. It’s used to signal if the police are present or on their way to a location, or, to signal other people that there is danger in that area. Or also used as a way of checking if an area is safe or not.
Person 1: I was walking past the Grove and somebody hit me with that 3-Tone Whistle and I dipped.