Shift one oscillator a few cents sharp and hear two voices fuse into a lush chorus, the same micro-detune trick that makes orchestras and supersaw leads sound enormous.
In the world
In a symphony, no two violinists play at exactly the same pitch. That micro-detune between dozens of bows is why an orchestra sounds enormous and alive compared to a single player. Every unison synth patch, from 1980s supersaw leads to modern ambient drones, exploits the same trick.
When two oscillators play the same note but one is shifted by just a few cents (hundredths of a semitone), the tiny frequency difference creates slow constructive and destructive interference. On the scope you can see the combined waveform breathe in and out - the amplitude swells and dips in a slow pulse called beating.
At 5-10 cents apart the beating is gentle and lush: a chorus effect, thickening the tone without changing its pitch. Push the offset wider and the beating speeds up until the ear starts hearing two separate notes instead of one rich voice. This is the simplest way to fatten any patch - two detuned oscillators cost nothing and sound like a room full of players.
Did you know?
The entire string section of an orchestra is detuned by nature - 16 violinists are never perfectly in tune. Synthesizer designers spent decades trying to recreate that imperfection on purpose, and the Roland Juno-60's famous chorus circuit is just two oscillators a few cents apart.
Explore
Twin flame columns burn side by side in the 3D scene. Drag the slider to set detune from 0 to 50 cents. At zero the flames merge into one pillar; spread them apart and they breathe at the beat frequency, swelling and dimming in a slow pulse you can see and hear.
Listen: at exactly 0 cents the scope trace is steady. As you push Fine up, the breathing begins. By 20 cents it is fast enough to sound rough. The sweet spot for a lush unison is somewhere between 3 and 8 cents.