Main Page | See live article | Alphabetical index Measure can mean: To perform a measurement. In mathematics, a measure is a way to assign non-negative real numbers to subsets of a given set, in order to "measure their sizes or probabilities". See measure (mathematics) for a treatment of the concept. In music, a measure is a unit of time in Western music. It represents a regular grouping of beats, a meter, as indicated in musical notation by the time signature. Measures are also called barss, since measures are separated by vertical bars (called bar lines) in musical notation. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.