Double whole note

The Brevis or double whole designated in the notation (Music) a note value of usually two whole notes. The spelling as lying transversely rectangle comes from mensural notation, in this time, the Brevis could be three times as long as the next smallest note value under certain conditions. In addition, today the spelling of one of two vertical lines framed whole note is in use. Two closely spaced whole notes, however, only describe the tone duration of a whole note, and that is when (on strings) a sound as a double grip on two strings to be played simultaneously or when two different voices that are listed in a note line, in line ( Prime) meet.