In the essay "Black Men and Public Spaces" (originally entitled "Just Walk On By") by Brent Staples, whistling classical music and wearing a cowbell in bear country are paradoxical uses of making music sounds.
A paradox is roughly defined as a true yet contradictory statement. Whistling classical music is a light-hearted, entertaining activity. Wearing a cowbell in bear country is also a way to make musical noises, but it is for the reason of survival and to ward off attack.
In the essay, the character Staples compares his whistling classical music (Vivaldi) as an equivalent of “the cowbell that hikers wear when they know they are in bear county.” Some feel he may have meant that his whistling is a way to inform others that he is no threat to them, despite other's inklings that he is one (pertaining to issues of race, age, and gender).
Find some interesting interpretations of the paradox in the Staples essay here.