Foundation
Definition
Foundation is what stays the same.
In this model, Foundation is the kick drum. Not as a metaphor, not as one possible anchor among many — the kick is the single reliably detectable element in a live techno audio signal in real time. Everything in this model derives from what can be measured about the kick.
The kick is chosen because it occupies a unique position in the frequency spectrum. In techno, the kick lives in the sub-bass and low-bass range (~30–120 Hz) with a transient click extending into the low-mids. No other element in a typical techno mix occupies this space with the same energy and regularity. This makes it isolatable even in a dense, compressed live signal where individual synths, hats, and percussion are blurred together.
Why the Kick and Nothing Else
This is a real-time system analyzing a summed stereo signal (not stems, not MIDI, not pre-labeled data). In a live context — audio from a mixer, from a sound system, from a DJ’s output — the signal is a single waveform containing everything at once.
Attempting to extract multiple independent sources from this signal in real time is unreliable:
What we receive: A single stereo audio stream.
Everything mixed together.
What we can isolate: The kick.
It has unique spectral and temporal properties
that no other element in techno shares.
What we cannot isolate Hi-hats from noise sweeps.
reliably in real time: Synth layers from each other.
Vocal samples from reverb tails.
Claps from snares.Rather than building a model on unreliable multi-source extraction, this model builds everything from one trustworthy signal. The kick is the anchor. Everything else is measured relative to it — as changes in the spectral environment around the kick, which is what Variance captures.
Properties
Foundation exposes three properties, each described in detail on its own page:
┌──────────────────────────────────────────────────────────────┐
│ FOUNDATION (the kick) │
│ │
│ Weight ──── continuous (0→1) ──── how heavy it feels │
│ See: Weight │
│ │
│ Presence ──── continuous (0→1) ──── how clearly it is │
│ + binary gate perceived in the mix │
│ See: Presence │
│ │
│ Sustain ──── categorical ───────── how it decays │
│ (dry / mid / wet) after impact │
│ See: Sustain │
│ │
└──────────────────────────────────────────────────────────────┘These three properties together describe everything the model needs to know about the stable, repeating element of the performance.
Foundation Over Time
Foundation is defined by its stability. It is the element that repeats, that holds the floor, that gives the listener (and the visual system) something to anchor to.
Foundation over time (stable):
████████████████████████████████████████████ ← Foundation line
(stable, consistent, the anchor for everything else)
X X X X X X X X X X X ← Kicks expressing it
| | | | | | | | | | |
beat beat beat beat beat beat beat beat beatWhen Foundation is stable, Weight may vary gradually (a heavier kick, a lighter kick), Presence stays high, and Sustain holds its category. The visual system has a reliable, continuous signal to drive from.
Foundation over time (breaking):
████████████████████████░░░░░░░░░░░░░████████████████
│ │
Foundation breaks Foundation returns
(kick disappears) (kick comes back)
Presence drops Presence rises
Gate opens Gate closes
(after threshold) (after threshold)
Story transitions Story transitionsWhen Foundation breaks — when the kick disappears from the mix — the model enters a fundamentally different state. See Presence for details on how this is detected and confirmed.
What Foundation Is Not
Foundation is not “the bass.” A bassline is a melodic/harmonic element that may or may not be present, may change pitch, may have complex rhythmic patterns. Foundation is the kick — a percussive, rhythmic, spectrally consistent element.
Foundation is not “the rhythm.” A track can have complex polyrhythmic percussion while the Foundation (the kick) remains a steady four-on-the-floor pattern. Foundation is specifically the lowest-frequency rhythmic anchor.
Foundation is not “everything below 200 Hz.” The frequency range of the kick is one of its identifying properties, but Foundation is defined by the combination of spectral content, transient shape, and rhythmic regularity — not by a frequency cutoff alone.
When Foundation Is Absent
If the kick is not present in the mix, Foundation is absent. The model does not attempt to find a substitute anchor. There is no fallback.
This means:
- During breakdowns where the kick is removed, Foundation = absent
- During transitions between tracks where the kick briefly drops, Foundation may briefly be absent (but Temporal Thresholds prevent false transitions)
- During ambient interludes or noise sections, Foundation = absent
- When Foundation is absent, Story = null
This is a deliberate constraint. The model’s accuracy comes from its narrow scope. By committing to the kick as the single source of truth, every value the model produces is grounded in something real and measurable.
The Kick in Techno
The four-on-the-floor kick pattern is the defining rhythmic feature of techno. It is what makes the model’s single-source approach viable for this genre specifically.
Four-on-the-floor at 128 BPM:
Bar 1 Bar 2
X . . . X . . . X . . . X . . . X . . . X . . . X . . . X . . .
1 2 3 4 1 2 3 4
Every beat. Predictable. Consistent.
The system knows exactly when to expect the next kick.
With Pro DJ Link: the system knows the beat grid.
It doesn't need to "detect" kicks — it knows where they are
and measures what is there at each beat position.This regularity is what makes the kick uniquely useful. The system knows when to look (every beat, from the beat grid). It only needs to measure what’s there at each beat position — how much energy, how it decays, how clearly it cuts through.
Related Pages
- Weight — how heavy the kick feels
- Presence — how clearly the kick is perceived
- Sustain — how the kick decays
- Variance — what changes around the kick
- Story — how Foundation and Variance combine into named moments