What is a measure in the context of music notation?

In music notation, a measure is defined as a group of notes and rests that are organized together and separated by vertical lines, known as bar lines. Each measure contains a specific number of beats that is determined by the time signature of the piece. This structure allows musicians to read and interpret the music more easily, ensuring that rhythms and phrasing are clear.

While other elements of music notation are important, they do not accurately define what a measure is. For instance, a musical rest refers to the absence of sound for a certain duration, and while it can occur within a measure, it is not a measure itself. Similarly, a clef indicates the pitch of the notes but does not represent a grouping of notes and rests. Lastly, the instrument used to perform the music contributes to the sound but is unrelated to the concept of a measure in notation. Understanding measures is essential for musicians to effectively learn, perform, and compose music.