Double whole note either of two ways: by a hollow oval note head, like a whole note, with one or two vertical lines on either side, as on the left of the image, or as the rectangular shape also found in older notation, shown in the middle of the image (; ). Because it lasts longer than a bar in most modern time signatures in common use, the breve is rarely encountered except in English music, where the half-note is often used as the beat unit . A related symbol is the double whole rest (double rest or breve rest), which usually denotes
Note value of the 18th century and earlier the amount by which the dot augmented the note varied: it could be more or less than the modern interpretation, to fit into the context. To divide a note value to three equal parts, or some other value than two, tuplets may be used. However, see swung note and notes inégales. Although note heads of various shapes, and notes with and without stems appear in early Gregorian chant manuscripts, many scholars agree that these symbols do not indicate different durations, although the dot is used for augmentation. See neume. In the 13th century, chant