from The Century Dictionary.
- noun In musical notation, same as
rhythmical signature(which see, under rhythmical).
Sorry, no etymologies found.
The circle has disappeared entirely as a measure-sign, but the broken circle still survives, and from it are derived the familiar signs [common-time symbol] and
Beat-Note: A note of the denomination indicated by the measure-sign as the unit of note-value in a given measure.
The numeral and the beat-note thus grouped constitute the measure-sign.