Tempus
Tempus (Latin “time”) denotes in the mensural notation of the Middle Ages and Renaissance the division of the brevis: in three with the full circle, in two with the half circle. From the open half circle arose today's C for 4/4 time, and crossed through it became the alla breve sign.
- Meaning
- time, division of the brevis
- Full circle
- tempus perfectum, in three
- Half circle
- tempus imperfectum, in two
- Today
- C = 4/4, ¢ = alla breve (2/2)
- Period
- Middle Ages to Renaissance
From the circle to the C
The page Rhythm says it briefly: four-four time is also written “C”, from tempus imperfectum. The page Notation symbols explains the origin in more detail: mensuration signs stand at the beginning of a voice as the time signature does today. The circle counted as the symbol of perfection, of the Trinity, which is why the division in three is called “perfectum”. The open half circle shows the “imperfect” time in two.
| Sign | Name | Division | Modern equivalent |
|---|---|---|---|
| Full circle | Tempus perfectum | brevis = 3 semibreves | roughly 3/2 |
| Circle with dot | Tempus perfectum, prolatio perfecta | brevis = 9 minims | roughly 9/8 |
| Half circle with dot | Tempus imperfectum, prolatio perfecta | brevis = 6 minims | roughly 6/8 |
| Half circle | Tempus imperfectum | throughout in two | roughly 4/4 or 2/2, today's C |
From the half circle without a dot arose, according to the page, today's C for 4/4 time, crossed through it became the alla breve sign. The ¢ stands for 2/2 time, that is two half notes per bar. The signs with a dot determine the prolatio, the division of the semibreve. That gives roughly 9/8 for the circle with a dot and 6/8 for the half circle with a dot, frequent in French music of the 14th century, for instance in Guillaume de Machaut.
C and ¢ in the sheet music archive
Guitar
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Gitarrenschule, Stück Nr. 9 Johann Kaspar Mertz · from: Guitar-Skole · guitar · 1 page
The time signature is the C, the descendant of the half circle: 4/4.
Piano
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Mondscheinsonate, 1. Satz Ludwig van Beethoven, Sonata No. 14 in C♯ minor, op. 27 No. 2 · piano · 5 pages
The time signature is the crossed-out C (¢), the alla breve sign, four sharps in the key signature.
Voice and piano
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Ich lade gern mir Gäste ein Aria from Die Fledermaus · voice and piano, with chords for guitar
Also the crossed-out C (alla breve), “Allegro non troppo”, five flats in the key signature.
The sign ¢ appears in Beethoven and in the Fledermaus aria, the plain C for instance in Mertz. The two signs are not interchangeable: the crossed-out one stands for alla breve time. A “4/4” would be wrong for the Moonlight Sonata.
Common mistakes
- Equating C and ¢: The crossed-out sign is alla breve time.
- Taking the C for “common time”: The letter comes from the half circle of tempus imperfectum.
- Reading mensuration signs like time signatures: They fix the division of time, the modern equivalent is only approximate.
Continue on Maikstrings
Related terms
Four-four timeBar / measureTime signatureBarlineMensural notationHalf noteQuarter note
Editor: Maik Krohm · reviewed on 3 October 2026
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