Time & meter
Music needs a shared clock. Tempo sets the clock’s rate; beats are the points we count; subdivision creates editable positions between them; meter groups beats into repeating bars.
rate→beat
count→subdivision
grid→events + rests
pattern
From BPM to an editable grid
step duration = 60 / BPM / subdivisionAt 120 BPM, one beat lasts 0.5 s. With two steps per beat, each eighth-note position lasts 0.25 s.1 & · 2 & · 3 & · 4 &X structural onset · x lighter onset · empty = no onsetThe familiar sixteen-step sequencer is only one case: one bar can have 6, 8, 12 or 16 editable positions. Compute the grid from meter and subdivision instead of assuming that every bar is 4/4 with sixteenth notes.
Three beats, split into two eighth-note positions each.
Four beats, split into four sixteenth-note positions each.
Tempo and meter answer different questions
| Coordinate | Meaning | Example |
|---|---|---|
| Tempo | How fast does the reference beat recur? | 120 BPM |
| Meter | How are beats grouped and counted? | 3/4, 4/4, 5/4 [3+2] |
| Subdivision | How many editable positions divide one beat? | ×2 gives eighth-note positions |
| Swing | How are nominally equal subdivisions displaced? | long–short instead of exactly equal |
The meter library used by Build
Read each entry as a repeating count, not as a genre. The same meter can support many styles; the grouping says where a listener is most likely to feel the internal landmarks.
| Frame | Default grouping | Useful alternative |
|---|---|---|
2/4 | 1 + 1 | compact direct pulse |
3/4 | 1 + 2 | one anchor plus two continuations |
4/4 | 2 + 2 | 3 + 1 |
5/4 | 3 + 2 | 2 + 3 |
6/8 | 3 + 3 | 2 + 2 + 2 |
7/8 | 2 + 2 + 3 | 2 + 3 + 2 or 3 + 2 + 2 |
9/8 | 3 + 3 + 3 | 2 + 2 + 2 + 3 |
12/8 | 3 + 3 + 3 + 3 | six groups of two |
Build then chooses 2, 3 or 4 editable steps per perceived beat. Beat recipes place attacks on that derived grid; they do not assume a permanent sixteen-step bar.
beats × subdivisions3/4 ×2 = 6 positions per bar. 4/4 ×2 = 8. Changing meter must rebuild or explicitly reinterpret event positions.Sound, silence and articulation occupy the same clock
A note event has onset, duration, velocity and gate. A rest reserves time and states that silence is intended. Deleting an event only leaves an unassigned position: an empty slot is not an intentional rest.
| Thing | What it controls |
|---|---|
| Duration | How much musical time the event owns |
| Gate | When note-off happens inside that duration |
| Velocity | Onset energy/accent, depending on the instrument |
| Rest | Explicit silence at voice, part or whole-arrangement scope |
Groove and articulation are separate controls
| Change | Moves what? | Audible result |
|---|---|---|
| Timing | The onset earlier or later | Push, drag, swing or looseness |
| Velocity | The event’s onset energy | Accent hierarchy |
| Gate | Note-off inside the slot | Staccato or connected articulation |
| Probability | Whether an event occurs | Variation; not human timing by itself |
timing ≠ velocity ≠ gate ≠ probability“Humanize” is not one control. Name the dimension you are varying so the result remains understandable and repeatable.Polymeter: cycles share time, not a bar line
Two parts may use the same step duration while repeating after different numbers of steps. Their onsets drift against each other and meet again at the least common multiple of their cycle lengths.
8 stepsstable reference6 stepsrotating relationLCM(8, 6) = 24both cycles restart togethermeeting length = LCM(a, b)Polymeter changes cycle grouping. Polyrhythm instead compares different pulse divisions inside a shared span.- Choose 3/4 and compare Beat pulse with Offbeats.
- Switch to 4/4: confirm the rebuild instead of silently retaining old positions.
- Choose Breathing line and find the explicit rest at the end of every bar.
Terms, relations and sources
Key terms
tempometersubdivisionrestRelated chapters
Rhythm & interactionForm & arrangementDetailed lookup
Generative rhythmNotation legendEvidence
Editorial sourcesModels state their boundary; tradition-specific claims require specialist sources.