A time signature says how many beats go by before the cycle starts again. It looks like a fraction, but all it is really doing is deciding where you feel the strong beats.
Clap along to a song and every few claps one lands on "the front". That cycle is the time signature. Most pop songs come back around every four beats, which is 4/4.
The top number and the bottom number
In 4/4 the bottom 4 means "count quarter notes as the beat" and the top 4 means "four of them per bar". So 3/4 cycles every three quarter notes, and 6/8 cycles every six eighth notes. Press the rows below to hear each count. Watch where the weight lands.
- 4/4 — cycles on four. The pop default
- 3/4 — cycles on three. The waltz count
- 6/8 — 1·2·3 / 4·5·6. Two groups of three
How many beats before the cycle repeats, and which of them you feel as strong. It sets the walk of the whole piece.
Three beats means "three steps per cycle"
3/4 counts one, two, three. Step one is strong and the other two are light. Waltzes and ballads use it, and it feels like it sways compared to four. If your ear is used to four, it can be hard to count at first — tap your knee and repeat "strong, light, light" three at a time.
6/8 is not three-four
This is the classic stumbling point. Six eighth notes take exactly as long as three quarter notes, so 3/4 and 6/8 fill the same amount of time. They are still treated as different meters, because 3/4 counts three single beats while 6/8 counts two groups of three. One strong point versus two — and that alone changes how the music walks.
- Play in 3/4
C | F | G | C
- Play in 6/8
C | F | G | C
Five and seven exist too
Not every meter is a four or a three. Fives and sevens are counted in uneven groups like 2+3 or 2+2+3. Game soundtracks and progressive rock are full of them. Chapter 23 goes into it; if you want to try one now, the meter picker below has them.
Generate in 6/8. The same chords will produce a melody with a different rhythmic feel than 4/4 gives you.
Generate a melody in 6/8A time signature sets the cycle length and where the weight falls. 3/4 and 6/8 last the same and are still different.