I have defined keynote as a regular sound underpinning other more fugitive or novel sound events. The keynotes of the farm were numerous, for farming is a life with little variation. Keynotes may influence the behavior of the people or set up rhythms that are carried over into other aspects of life. One example will have to suffice. In the Russia of Tolstoy, the peasants kept whetstones in little tin boxes strapped to their waists, and the rhythmic rattling of these boxes formed a vernacular keynote during the haying months.

Schafer, Murray R, The Soundscape- Our Sonic E…, loc. 172