The whole rest symbol is a music notation sign that means “silence for the duration of a whole note.”

What the whole rest symbol looks like

  • It is a small black rectangle.
  • It hangs from the 4th line of the staff (like an upside‑down hat).
  • This is how you tell it apart from the half rest, which sits on the 3rd line instead.

How long a whole rest lasts

  • In most basic time signatures like 4/4, a whole rest lasts 4 beats, the same as a whole note (semibreve).
  • Each type of rest matches the value of a note (quarter rest = quarter note, etc.), and the whole rest is the “full‑measure” version in common meters.

Special rule: silence for a whole measure

  • By convention, when a full measure is silent, you use a whole rest symbol, even if the time signature is not 4/4 (for example, in 3/4).
  • So the whole rest often doubles as the “entire bar is silent” symbol in many styles of notation.

Extra: Unicode / text version

  • There is a dedicated Unicode character for the musical whole rest: 𝄻 (Musical Symbol Whole Rest), which can be used in digital text settings.

TL;DR: The whole rest is the hanging rectangle on the 4th line of the staff that usually means 4 beats of silence and is commonly used to mark an entire bar of rest.

Information gathered from public forums or data available on the internet and portrayed here.