Bars and simple time signatures
Music theory · Rhythm · Level 1 · 10 min
Beats group themselves into regular packets, with a stronger first beat: these are bars (measures in American English). On the score they are separated by bar lines. A double bar line marks the end of a section; a thick double bar (final bar line) the end of the piece.
The time signature
At the start of the staff, right after the clef (and key signature), two stacked numbers give the time signature (meter):
- the top number: how many beats per bar;
- the bottom number: which note value gets one beat (4 = quarter, 2 = half, 8 = eighth).
| Time signature | Meaning | Strong / weak beats | Examples |
|---|---|---|---|
| 2/4 | 2 quarters per bar | STRONG-weak | marches, polkas |
| 3/4 | 3 quarters | STRONG-weak-weak | waltzes, minuets |
| 4/4 (or C) | 4 quarters | STRONG-weak-medium-weak | the vast majority of pop |
| 2/2 (or ¢, alla breve, "cut time") | 2 halves | STRONG-weak | fast marches, overtures |
The "C" for 4/4 does not actually stand for common time: it is a leftover from medieval notation (an incomplete circle). The crossed C (¢) means you beat in half notes: two beats per bar, so it feels twice as flowing.
A bar in three
The famous Minuet in G (long attributed to Bach, actually by Christian Petzold): feel the stressed first beat, then two lighter ones.
M:3/4 L:1/4 Q:1/4=110 K:G d G/A/B/c/ | d G G | e c/d/e/f/ | g G G |]
The pickup (anacrusis)
Many melodies start before the first downbeat, in an incomplete bar: the pickup, upbeat or anacrusis. The missing beats are "given back" in the last bar. Amazing Grace (3/4) begins on beat 3:
M:3/4 L:1/4 Q:1/4=80 K:G D | G2 B/G/ | B2 A | G2 E | D2 |] w: A-maz-ing_ grace how sweet the sound