Whole noteIn music, a whole note or semibreve is a note notated with a hollow oval note head, like a half note, and no note stem (see Figure 1). Its length is equal to four beats in 4/4 time. Most other notes divide the whole note; half notes are played for one half the duration of the whole note, quarter notes are each played for one quarter the duration, etc. The note twice the length of the whole note is the double whole note (or breve).
A similar symbol is the whole rest, which usually denotes a silence for the same duration. However, it is often used to denote a rest lasting a full bar, whether that bar lasts four beats or not - for example, it is often used to denote a full bar rest in 3/4 time. Whole rests are drawn as filled-in rectangles hanging under the second line from the top of the musical staff.
Figure 1. A whole note and a whole rest.