# Spectrogram

> A scrolling spectrogram (waterfall) for Python — frequency over time in color, with magma, viridis or any palette, drawn fast enough for live audio.

Source: https://albakore.github.io/pyzed/audio/components/spectrogram/

(Image: Two spectrograms scrolling left as a song plays: kicks as columns at the bottom, chords as bright lines)

**In plain words:**

A spectrogram is a spectrum analyzer with memory: time runs from left to right, pitch from bottom
to top, and the color says how loud each pitch was. You can see a song's rhythm and chords in it.

```python
ui.audio.Spectrogram(magnitudes=engine.spectrum(512), history=160, colors="magma")
```

Every render that receives a **new** `magnitudes` list adds a column on the right; redrawing for
any other reason (a hover, another widget) does not, so the speed follows your updates. It keeps
the last `history` columns.

Loudness is quantized into `levels` colors and every cell of one color is drawn in a single
shape, so even 160 columns × 64 bands stay cheap to draw.

| Property | Default | What it does |
| --- | --- | --- |
| `magnitudes` | `()` | dB per frequency bin (like `node.spectrum()`). |
| `width`, `height` | `360`, `140` | Size in pixels. |
| `history` | `120` | Columns kept. |
| `bands` | `48` | Rows (log-spaced bands). |
| `min_db`, `max_db` | `-90`, `0` | Range of the colors. |
| `colors`, `levels` | `"magma"`, `24` | Palette and how many color steps. |
| `sample_rate`, `spacing` | `48000`, `"log"` | Like [`Spectrum`](https://albakore.github.io/pyzed/audio/components/spectrum/): how the bins are spaced. |