 In works of the Ars Nova from the 14th century, this was used to indicate a temporary change in metre from triple to duple, or vice versa.This usage became less common in the 15th century as open white noteheads became the standard notational form for minims (half-notes) and longer notes called white mensural notation.Similarly, in the 16th century, a form of notating secular music, especially madrigals in was referred to as "chromatic" because of its abundance of "coloured in" black notes, that is semiminims (crotchets or quarter notes) and shorter notes, as opposed to the open white notes in , commonly used for the notation of sacred music.