Music theory The basics
Rhythm and metre
Note and rest values with UK and US names, dots, ties, time signatures, simple and compound metre, and how to count.
Practise this on its own page: Open the metronome.
Beats and bars
The beat is the steady pulse you might tap your foot to. Beats are grouped into bars (called measures in American English), and bar lines on the stave show where each bar ends.
Metre is the pattern of beats in each bar. Music with two beats in a bar is in duple metre, three beats is triple metre and four beats is quadruple metre.
Note values
Note values tell you how long each note lasts. British and American books use different names for the same notes, so it helps to know both.
| UK name | US name | Crotchet beats in 4/4 |
|---|---|---|
| Semibreve | Whole note | 4 |
| Minim | Half note | 2 |
| Crotchet | Quarter note | 1 |
| Quaver | Eighth note | 1/2 |
| Semiquaver | Sixteenth note | 1/4 |
Rests
A rest is a silence of a set length. Each note value has a matching rest: a semibreve rest (whole rest), minim rest (half rest), crotchet rest (quarter rest), quaver rest (eighth rest) and semiquaver rest (sixteenth rest).
Count rests just as carefully as notes. The silence is part of the rhythm.
Dots, ties and beams
A dot after a note makes it longer by half of its own value. A dotted minim lasts a minim plus a crotchet, which is three crotchet beats. A second dot adds half the value of the first dot.
A tie is a curved line joining two notes of the same pitch. You play the first note and hold it through the second without playing it again.
Beams are the straight lines that join groups of quavers or shorter notes, which makes the beats easier to see.
Time signatures in simple metre
In simple metre each beat divides into two. The time signature at the start of the music has two numbers: the top number tells you how many beats are in each bar, and the bottom number tells you which note value gets one beat.
A bottom number of 4 means the crotchet gets the beat. So 2/4 has two crotchet beats per bar, 3/4 has three and 4/4 has four. A large C in place of the numbers means common time, which is the same as 4/4.
Compound metre
In compound metre each beat divides into three, so the beat is always a dotted note. In compound time signatures the bottom number shows the size of each small division, not the beat.
For example, 6/8 has six quavers in a bar, grouped into two beats of three quavers each. Each beat is therefore a dotted crotchet.
Counting out loud
- Count the beats with numbers: 1, 2, 3, 4.
- In simple metre, say 'and' for the second half of a beat: 1 and 2 and.
- For semiquavers, add 'e' and 'a': 1 e and a, 2 e and a.
- In compound metre, one common system counts the three parts of a beat as 1 la li, 2 la li.