Techniques
The oscilloscope music technique reference — drawing with sound, phase manipulation, multiple objects, brightness, harmony, fidelity and 3D, in one place.
Everything else in these docs explains what the controls do. This section explains what to do with them.
Oscilloscope art has a real body of technique behind it, developed over about fifteen years by a small number of people, and almost all of it lives in video tutorials rather than text. These pages are the written version: the operations that turn a scope from a signal viewer into an instrument, why each one exists, and how to perform it in OSC-1.
Start here
If you read one page, read Fidelity. Nearly every "why does my image look wrong" question is answered there, and the answer is usually not the one people expect.
The one constraint everything follows from
A computer screen draws by addressing pixels, and it can stop drawing — lift the pen, skip a region, come back later.
An oscilloscope cannot. There is one dot, it is always somewhere, and it is always on. It moves continuously and you see the trail. There is no pen to lift, no fill, no layers, no second object.
Every technique on these pages is a consequence of that. Once you internalise it, the medium's strange rules stop being arbitrary:
- You cannot draw two things, because there is one dot — so you take turns fast enough that the eye is fooled. See Multiple objects.
- You cannot brighten one part of a figure, because there is no brightness input per point — so you slow the dot down there instead. See Brightness.
- You cannot draw a perfectly sharp corner, because a corner is an infinitely fast change and audio has a speed limit. See Fidelity.
- You cannot usually play two notes at once, because adding a second sound changes the path rather than layering on it. See Harmony.
The pages
| Page | What it covers |
|---|---|
| Fidelity | Sample rate, Nyquist, why corners round off, and the drawing-rate trade-off. The highest-value page here. |
| Phase | Phase as position-in-the-figure. Trace, dash, offset — and why their order matters. |
| Multiple objects | Why summing two shapes fails, the four ways around it, and phase cutting as the real answer. |
| Brightness | Controlling brightness with no brightness control: path density, beam speed, and the Z-axis dead end. |
| Harmony | Where the chords come from. Copies as frequency ratios, and why just intonation sits still while equal temperament wobbles. |
| 3D | Projection, hidden-line removal as a sonic optimisation, path routing, and vertex budgets. |
| Effects dictionary | A two-way table: what each audio effect looks like, and what each visual transform sounds like. |
The idea worth carrying through all of them
The image and the sound are not two outputs of one process. They are the same signal. Anything that changes one changes the other, always, with no exceptions and no way to opt out.
That sounds like a limitation and is mostly a gift. It means every visual decision is a musical decision you have already made, and a piece that looks composed tends to sound composed. It also means the medium punishes treating the sound as a soundtrack: if the way you achieved a visual effect is inaudible, you have made a video, not oscilloscope music.
Related
- Getting started — first signal on screen
- Shape tools — the generators these techniques are applied to
- Beam effects — the display side: phosphor, bloom, persistence
- Hardware — using a real CRT