How Do I Play Oscilloscope Shapes With MIDI Chords?
To play oscilloscope shapes with chords, open BeamTracer OSC-1 in CREATOR mode and turn on CHORD FIGURE in the synth bar. Hold two notes on a MIDI or computer keyboard. LOCK TO SHAPE bends the current drawing with that interval; switch the lock off to let the chord figure move over it at its own pitch.
LOCK TO SHAPE is off here. A held C–G fifth moves over the circle; modulation adds loops and pitch bend changes its rotation. This preview is silent. An audible recording appears below.
How do I start with a circle and play a chord into it?
A circle makes the chord’s contribution easy to see. You can return to more elaborate source drawings after learning how the lock behaves.
- Open OSC-1 and select CREATOR.
- Open GENERATORS → LISSAJOUS and choose PRESET → Circle. Set AMP X: 0.65 and AMP Y: 0.65, then let the circle play.
- Turn on CHORD FIGURE in the synth bar. LOCK TO SHAPE turns on with it.
- Hold C3 + G3 on a MIDI keyboard. Without a controller, hold Z + B on your computer keyboard while focus is outside a text field.
- Keep C3 held and change G3 to E3, then C4. On the computer keyboard, use Z + C, then Z + Q.
- Open EXPORT → VIDEO and choose SHAPE → 1:1, then RECORD LIVE INPUT. Close the export panel, play your phrase, then reopen it and choose STOP RECORDING to download the WebM.
The locked take changes from C3–G3 to C3–E3 to C3–C4, then raises modulation. The source circle stays part of the drawing throughout. These examples use AMP X / AMP Y: 0.65 and the VECTOR DISPLAY scope preset with Intensity: +1.3.
The on-screen piano also plays the figure. On a touch screen, hold two keys with two fingers. If a MIDI controller does not light the keys, open Settings → MIDI and check the input connection. The MIDI and hardware guide covers device setup.
What do the different intervals draw?
The held interval gives the figure a small whole-number ratio. The drawing you see also includes the source underneath it, so the result over a circle differs from a standalone Lissajous preset.
| Held notes | Interval | Chord-figure ratio | Computer keys |
|---|---|---|---|
| C3 + G3 | Perfect fifth | 2:3 | Z + B |
| C3 + E3 | Major third | 4:5 | Z + C |
| C3 + C4 | Octave | 1:2 | Z + Q |
Hold one pair long enough to see its outline before changing notes. A quick run across several keys produces a different gesture from a held chord. Release both notes to let the figure fade back into the source.
For the relationship between drawing repetition and harmony, read where oscilloscope music’s chords come from. Here the useful performance control is the interval you hold.
When should I turn LOCK TO SHAPE off?
Keep the lock on when you want the played figure to bend the source without drifting across it. With a repeating generator, the figure follows the source’s drawing rate. The picture becomes slightly smaller while locked so the combined shape has room to bend.
Turn the lock off when you want the chord’s own pitch to drive a moving pattern over the source, as in the opening example. A file or microphone input does not always have a fixed drawing cycle to lock onto. Judge the combination with the actual source you plan to perform over.
CHORD FIGURE does not initialize the synth when you press a key. Leave INITIALIZE alone for this circle-and-figure recipe. If you deliberately initialize the synth and leave its switch on, it plays along with the figure. Switch the synth off to remove its sound while keeping the figure.
How do velocity and the wheels change the result?
A harder MIDI key press makes a larger figure. Letting go releases the figure gradually instead of cutting it off at once. Try a soft fifth, release it, then play the same fifth harder.
The notes stay C3 and G3. The first press uses velocity 34; the second uses 120. Each release lets the circle recover.
Use PITCH for rotation and MOD for a rose-like figure with additional loops. Return both wheels to their starting positions before comparing intervals. Otherwise the expression from one phrase carries into the next.
How do I save the sound and picture I just played?
Use RECORD LIVE INPUT for the performance. Offline RENDER VIDEO works from a loaded or generated track; it does not replay the MIDI notes you played earlier. Choose the output shape and resolution before starting a take, and stop recording after the phrase has released.
Press Play to hear the locked take. The sound is the recorded OSC-1 output, including the source circle. Start with a low listening volume.
Review the saved WebM before sharing it. The synth guide covers the complete Chord Figure controls, and pricing lists current export access. These examples use the browser display; they do not demonstrate a physical oscilloscope or laser connection.
Hold a fifth, change one note, and watch the circle respond.
Try Chord Figure in OSC-1