---
name: kinetic-beat-slam
description: Percussive kinetic typography — short phrases slam in on a steady beat with distinct per-phrase entrances, optional rhythm chrome (metronome ticks, beat bar), then a locked finale.
metadata:
  tags: text, kinetic, typography, beat, rhythm, slam, percussive, punchy
---

# Kinetic Beat Slam

Short phrases hit one at a time on a **steady beat**, each with a _different_ entrance, then stack into a locked finale — the recipe for "punchy / rhythmic" text-forward pieces (taglines, manifestos, hype intros). The difference between generic and rhythmic is (1) one shared **onset array** driving every element, (2) **distinct** entrances per phrase rather than one reused helper, and (3) optional **rhythm chrome** that visibly keeps the beat.

## How It Works

A single tempo grid — `PULSE` seconds per sub-beat, `BEATS = [t0, t1, t2, …]` on that grid — is the rhythmic spine; every phrase entrance, accent, and chrome tick reads its time from it, so the piece locks to one pulse instead of drifting hand-tuned offsets. Each phrase gets a different transform axis (scale+blur slam / side snap / rise+rotate) with short attacks (0.35–0.6s on the hit), then the stack holds with a finite low-amplitude breath.

## Recipe

```html
<!-- inside a standard scene clip (hyperframes-core) -->
<div class="kbs-stage">
  <div class="kbs-line" id="p1"><span class="verb">Notice</span> more.</div>
  <div class="kbs-line" id="p2"><span class="verb">Decide</span> faster.</div>
  <div class="kbs-line" id="p3"><span class="verb">Act</span> now.</div>
</div>
<!-- optional rhythm chrome -->
<div class="kbs-metronome" aria-hidden="true"><i></i><i></i><i></i><i></i><i></i></div>
```

```css
.kbs-stage {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 120px 160px; /* title-safe margin */
}
.kbs-line {
  font-family: "Archivo Black", "League Gothic", sans-serif; /* embedded display face */
  font-size: 150px;
  line-height: 0.96;
  letter-spacing: -0.03em;
  color: #f5f5f5;
}
.kbs-line .verb {
  color: #ff5b2e; /* exactly one accent hue */
}
.kbs-metronome {
  position: absolute;
  bottom: 64px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 14px;
}
.kbs-metronome i {
  width: 6px;
  height: 28px;
  background: #ff5b2e;
  opacity: 0.25;
}
```

```js
// ONE tempo grid drives everything — phrases AND the metronome read it.
const PULSE = 0.4; // seconds per sub-beat
const BEATS = [PULSE * 1, PULSE * 5, PULSE * 9]; // phrase onsets, on the grid

// Distinct entrances per phrase (NOT one reused helper).
tl.fromTo(
  "#p1",
  { scale: 1.5, filter: "blur(16px)", opacity: 0 },
  { scale: 1, filter: "blur(0px)", opacity: 1, duration: 0.5, ease: "power4.out" },
  BEATS[0],
);
tl.fromTo(
  "#p2",
  { x: -320, opacity: 0 },
  { x: 0, opacity: 1, duration: 0.45, ease: "expo.out" },
  BEATS[1],
);
tl.fromTo(
  "#p3",
  { y: 90, rotation: 6, opacity: 0 },
  { y: 0, rotation: 0, opacity: 1, duration: 0.55, ease: "circ.out" },
  BEATS[2],
);

// Rhythm chrome: each tick flashes on the SAME grid, not a magic offset.
gsap.utils.toArray(".kbs-metronome i").forEach((tick, i) => {
  tl.to(tick, { opacity: 1, duration: 0.08, yoyo: true, repeat: 1, ease: "none" }, PULSE * (i + 1));
});

// Finale hold: floor (not ceil) so the repeat never overshoots data-duration;
// max(0,…) so a short hold never yields a negative repeat (GSAP reads negative as -1 = infinite).
const holdStart = BEATS[2] + 0.7,
  cycle = 1.6,
  holdDur = SCENE_DURATION - holdStart;
tl.to(
  ".kbs-stage",
  {
    scale: 1.01,
    duration: cycle / 2,
    ease: "sine.inOut",
    yoyo: true,
    repeat: Math.max(0, Math.floor(holdDur / cycle) - 1),
  },
  holdStart,
);
```

## Variations

- **Entrance easing by attack character** — `power4.out` hard slam ⭐ default hit · `expo.out` hardest snap (side-snaps, whip-ins) · `back.out(2)` overshoot pop (accents only, not body words) · `circ.out` heavy rise with momentum. Use **at least 3 distinct easings** across the piece.
- **Rhythm chrome alternatives** — a center beat bar or a `// label` monospace tag pulsing on-beat instead of the 5-tick metronome; mark any decorative that must survive a shader transition per `../../transitions/overview.md`.
- **Finale dressing** — stack + accent underline sweep ([css-marker-patterns](css-marker-patterns.md)); don't just leave the last phrase sitting.

## Values

| token             | range                | notes                                                                                        |
| ----------------- | -------------------- | -------------------------------------------------------------------------------------------- |
| BEATS spacing     | 1.2–1.8s             | <0.8s frantic, >2.5s loses the pulse; keep spacing even — it's a beat                        |
| entrance duration | 0.35–0.6s            | the hit must resolve before the next beat; exits ≤0.25s                                      |
| accent hue        | exactly 1            | the verbs; the rest mono white / near-black                                                  |
| display face      | 150px+, heavy weight | Archivo Black / League Gothic / Oswald — see `hyperframes-creative/references/typography.md` |

## Critical Constraints

- **One beat array, not scattered offsets** — every element times off `BEATS[]` / `PULSE`; this is the single biggest lever for "rhythmic".
- **Different entrance per phrase** — a reused `punchIn()` for all lines is the flat-but-competent tell. Vary the motion axis, reuse the ease _family_.
- **Finale repeat math**: `repeat: Math.max(0, Math.floor(dur / cycle) - 1)` — `Math.ceil` overshoots `data-duration` and trips the `gsap_repeat_ceil_overshoot` lint rule; a negative repeat is read by GSAP as `-1` (infinite).
- **No banned exit animations between scenes** — in a montage the _transition_ is the exit (`../../transitions/overview.md`); only a final scene may fade out.
- **Display font must be embedded** or it silently falls back at render — Anton / Bebas-as-literal are NOT embedded (`Bebas Neue` aliases to League Gothic; verify in `typography.md`).

## See also

`3d-text-depth-layers` (extruded depth on the slammed words) · `css-marker-patterns` (finale underline/circle) · `sine-wave-loop` (the finale breath) · `../adapters/gsap-easing-and-stagger.md` (easing vocabulary).
