Music theory visualizer: what a chord actually looks like

Who this is for

• Students learning intervals, chords and timbre
• Teachers who need a demo that runs on any laptop
• Anyone curious what harmony looks like

An octave is a picture, not a definition

Play C, then the C above it. In Spectrum Bars the second note lands a clear step to the right, and its harmonics line up with the lower note’s — that overlap is why an octave sounds like the same note twice. A fifth overlaps partly. A semitone barely overlaps at all, which is the beating you can both hear and see.

Chords, one key at a time

Hold A, D and G together for a triad and the display fills with the sum of three harmonic stacks; add the seventh and a new peak appears. Free play holds up to fourteen voices at once, so you can build a chord note by note and watch each addition arrive.

Pitch is not timbre

Switch between Keys, Pluck, Bass, Pad and Bell and play the same note. The fundamental does not move; the envelope in Oscilloscope and the harmonic content in the spectrum change completely. It is a quick way to show why two instruments playing one note sound like two instruments.

How to do it

1. Open BLOOB and press K, or click “Play the keys”
2. A–L are the white keys from C, W E T Y U the black keys; Z and X move the octave
3. Choose a literal scene with ← →: Spectrum Bars, Mirror EQ or Oscilloscope
4. Play an interval, then a chord, then switch instrument and play the same thing again