Rhythm and meter

Harmony is which notes sound; rhythm is when. This chapter covers how music counts time, how the grid of Ferrous Lineup counts it, and the meters that don’t go in twos and fours.

Beats and bars

Most music has a beat, the pulse you tap your foot to. The tempo says how fast it goes. Beats come in groups, with the first of each group leaned on a little: those groups are bars (or measures), and the meter says how they are made. Count along with almost any pop song and you count 1 2 3 4, 1 2 3 4: four beats to the bar, the first the strongest, the third a little strong too. A waltz counts 1 2 3.

The time signature writes the meter as two numbers: how many notes to the bar, and which note (see Time signatures).

Note values and steps

Notes are named by their length, each half the one before:

A dot after a note adds half its length again: a dotted quarter is three eighths, 6 steps; a dotted eighth is three sixteenths, 3 steps.

The piano roll and the channel rack count in steps, and a step is a sixteenth note: a bar of 4/4 has 16, a bar of 3/4 has 12 and a bar of 7/8 has 14. Time, in the harmony keys, says how many steps a bar has, and Length in the piano roll draws the lengths in the last column; drag a note’s right end for any other length.

A triplet fits three notes in the time of two: three eighths in a beat instead of two. Their starts fall between the steps of the grid. Demos and the MIDI files you open keep them exactly where they are played.

Two and three

In 2/4, 3/4 and 4/4, each beat is a quarter note that splits into two eighths: count 1 and 2 and 3 and. These are simple meters.

In 6/8, 9/8 and 12/8, the beat is a dotted quarter that splits into three eighths: 6/8 is two beats, counted 1 2 3 4 5 6, or 1-and-a 2-and-a. These are compound meters. A slow blues or a doo-wop ballad is often in 12/8: four beats, each a group of three.

3/4 and 6/8 both have six eighths to the bar, and that is where the fun starts:

• 3/4: three beats of two eighths: 1 & 2 & 3 &;
• 6/8: two beats of three: 1 2 3 4 5 6.

Much music of Spain and Latin America moves between the two, or plays both at once. The zamba and the chacarera of Argentina are written in 6/8, but their bombo drum plays 6/8 on its skin and 3/4 on its rim at the same time, and the tunes cross from one to the other, often in the bar before a cadence. That shift is the hemiola, the sesquiáltera of Spanish and Latin American music. Listen for it in the demo Zamba de mi esperanza, or try the Chacarera style in the Library. Leonard Bernstein built “America”, in West Side Story, on it: a bar of 6/8, then a bar of 3/4, “I like to be in | A-me-ri-ca”.

Strong beats, weak beats and syncopation

The beats of a bar are not equal. In 4/4 the first is the strongest and the third next. Rock, pop, soul and funk put the snare drum on the weak beats, 2 and 4: that is the backbeat, the clap of gospel music, and what makes a song groove.

Syncopation is an accent where the meter doesn’t expect one: on the “and” between beats, or a note that starts just before a strong beat and holds through it. A chord that arrives an eighth note early, before the bar line, is a push or anticipation: the band plays it with ^ on the chord sheet (see Shots, holds, rests and pushes). Latin music is built on syncopated patterns that repeat every bar or two, like the clave of Cuban music and the tresillo, three notes spread over eight eighths as 3 + 3 + 2.

Swing is the other great rhythmic idea of jazz: the eighth notes of each beat played long-short, closer to the first and third notes of a triplet than to two equal halves. See Swing and feel.

Odd meters

Some meters count their eighth notes in groups of two and three mixed. A group of three is half as long again as a group of two, so the beats are long and short, and a dance on them seems to limp: Turkish musicians call these meters aksak, “limping”.

The same 7/8 can limp two ways, so Ferrous Lineup writes the groups in the time signature: 3+2+2/8 is a lesnoto, 2+2+3/8 a rachenitsa. The drums, the bass and the chords all follow the groups. In the channel rack, each beat is shaded on its own, so you can see the long and short beats:

To hear it, open the demo Ajde Jano and count along with the kick: 1 2 3, 1 2, 1 2. To set an odd meter yourself, open Time and choose Any other: the top number, the bottom one and Beats grouped as, such as 3 + 2 + 2. The Library’s checkbox In 3+2+2/8 then shows the styles in that meter.

5/4 doesn’t always split 3 + 2. Take Five’s piano vamp goes 1 2 3 4 5, but the second movement of Tchaikovsky’s Pathétique Symphony, a waltz in five, goes 1 2 3 4 5, a short beat cutting in before each waltz step.

Meters that change

Some music changes meter as it goes. The Promenade from Mussorgsky’s Pictures at an Exhibition puts a bar of 5/4 next to a bar of 6/4, phrased like speech. A Bavarian zwiefacher, such as the demo Süsserl, mixes bars of two and three beats in an order the tune fixes, and the dancers know it by heart. In Ferrous Lineup each bar can have its own time signature: right-click a bar number in the playlist and choose under Time signature from bar (see Changing time signature partway through).