In order to keep accurate records (e.g. of birth and death) and to be alert to instances of straying, shepherds must perform frequent head-counts of their flocks.
Dating back at least to the medieval period, and continuing to the present in some areas like Slaidburn, farms were granted fell rights, allowing them access to common grazing land.
Their use is also attested in a "knitting song" known to be sung around the middle of the nineteenth century in Wensleydale, Yorkshire, beginning "yahn, tayhn, tether, mether, mimph".
[3] The counting system has been used for products sold within Northern England, such as prints,[4] beers,[5] alcoholic sparkling water (hard seltzer in U.S.),[6] and yarns,[7] as well as in artistic works referencing the region, such as Harrison Birtwistle's 1986 opera Yan Tan Tethera.
Jake Thackray's song "Old Molly Metcalfe"[8] from his 1972 album Bantam Cock uses the Swaledale "Yan Tan Tether Mether Pip" as a repeating lyrical theme.