Major third third is 13:10 (454¢) . A helpful way to recognize a major third is to hum the first two notes of "Kumbaya" or of "When the Saints Go Marching In". A descending major third is heard at the starts of "Goodnight, Ladies" and "Swing Low, Sweet Chariot". In equal temperament three major thirds in a row are equal to an octave (for example, A to C, C to E, and E to G; G and A represent the same note). This is sometimes called the "circle of thirds". In just intonation, however, three 5:4 major thirds are less than an
Four Thirds system Thirds cameras came to an end after the introduction of the mirrorless Micro Four Thirds format. Discontinued models include: The Four Thirds lens mount is specified to be a bayonet type with a flange focal distance of 38.67 mm. There are currently around three dozen lenses for the Four Thirds System standard. Before announcing that it would stop production of Four Thirds lenses in early 2017, Olympus produced about 20 lenses for the Four Thirds System under their "Zuiko Digital" brand. They are divided into three grades — Standard, High Grade and Super High Grade. High Grade lenses have faster