Polygonia comma Polygonia comma Polygonia comma, the eastern comma, is a North American butterfly in the family Nymphalidae, subfamily Nymphalinae. This butterfly is seasonally variable. The upperside of the summer form's hindwings are all black, whereas the winter forms hindwings are reddish orange. The underside of both forms is striped with dark and light brown. There is a silvery comma mark in the middle of the hindwing in both forms. Its wingspan is . The eastern comma may be spotted in woods near rivers, ponds, marshes, swamps, and other water sources. This butterfly seldom visits flowers, but rather feeds on sap, rotting
Syntonic comma just 6:5. This result was obtained by narrowing each fifth by a quarter of a syntonic comma, an amount which was considered negligible, and permitted the full development of music with complex texture, such as polyphonic music, or melody with instrumental accompaniment. Since then, other tuning systems were developed, and the syntonic comma was used as a reference value to temper the perfect fifths in an entire family of them. Namely, in the family belonging to the syntonic temperament continuum, including meantone temperaments. The syntonic comma arises in "comma pump" (comma drift) sequences such as C G D A E