The whole note or semibreve has a note head in the shape of a hollow oval—like a half note (or minim)—but with no note stem (see Figure 1). Since it is equal to four beats in 4
4 time, it occupies the entire length of a measure.
Other notes are multiples or fractions of the whole note. For example, a double whole note (or breve) lasts twice the duration of the whole note, a half note lasts one half the duration, and a quarter note (or crotchets) lasts one quarter the duration.
A related symbol is the whole rest (or semibreve rest). It usually applies for an entire measure, but may occasionally signify a rest for the duration of a whole note in longer time signatures such as 3
2 or 5
4. (An entire measure rest is drawn centered within the measure, whereas a rest lasting for a whole note is aligned to where the note would be.) Whole rests are drawn as filled-in rectangles generally hanging under the second line from the top of a musical staff, though they may occasionally be put under a different line (or ledger line) in more complicated polyphonic passages, or when two instruments or vocalists are written on one staff and one is temporarily silent.
The whole note and whole rest may also be used to denote a whole measure in music of free rhythm, such as Anglican chant, irrespective of the time of the measure. This usage can be applied generally to any form of music.