No Rock & Roll for Cows in Preston

I recently learned that rock and roll music was banned in Preston, Idaho for many years. Of course, I immediately assumed that folks in Preston regarded Elvis and his ilk as evil influences, and sought to protect their youth from rock's harmful effects.

But I was entirely wrong. Rock and roll music was banned in Preston, Idaho because cows simply don't like it. Soothing music must be played on the radio whilst cows are being milked, in order to give the best quality and quantity of milk. Who knew?