If your musical tastes extend to potential bouts of "involuntary gastrointestinal motility", a concert featuring the brown note may be just the ticket. According to an urban legend, the brown note is an ultra-low or infrasonic frequency which resonates with a person's gastrointestinal tract, causing an uncontrollable loss of bowel control. In theory, several thousand attendees of a performance would defecate simultaneously, creating a medical emergency of epic proportions and eliminating any chances of adding a second show.
The actual note or frequency connected with the note phenomenon is a matter of debate. Humans cannot hear frequencies below 20 Hertz (Hz), but they can feel physical effects from exposure to infrasonic frequencies played at high decibel levels, similar to feeling the pressure of subwoofer speakers in an expensive car stereo system or standing close to an oversized speaker at a rock concert.
The belief is that the note is achieved between 5 Hz and 9Hz, which would allegedly cause one's intestinal tract to resonate in the same way a thin crystal glass would resonate and ultimately shatter whenever an amplified soprano's voice was directed at it. In the case of the brown note, however, the results would be much harder to sweep away.
Several experiments and semi-scientific investigations have been conducted on the phenomenon over the years, mostly confirming its status as little more than an urban legend. When the brown note was performed in concert by musician Ben Folds, there were no reported incidents of involuntary defecation. An investigation by the television program MythBusters also failed to duplicate the effect, although volunteers did experience other symptoms while subjected to infrasonic frequencies.
The brown note is sometimes mentioned as a potential weapon of mass embarrassment in comic books and cartoons, but thankfully the note cannot be transmitted effectively over standard television or radio speakers. Arguably, the sustained effects of mass defecation would create serious health and environmental concerns, but the chances of a true criminal mastermind successfully broadcasting the note are slim to none. At best, a weaponized infrasonic sound generator might cause soldiers on a battlefield to become temporarily disoriented or unable to communicate.
This is not to suggest that the use of infrasonic frequencies is completely harmless, but the technology required to generate and broadcast a sustained brown note is generally not available to the general public. One might have to question the motives of anyone who did make the effort to obtain such a system, anyway. There's much more to life than generating involuntary gastrointestinal motility by way of massive subwoofers, isn't there?