JSFiddle - React, Tailwind, and code Playground

JavaScript

let audioCtx = new AudioContext();

let osc1 = audioCtx.createOscillator();
let osc2 = audioCtx.createOscillator();
let gain = audioCtx.createGain();

osc1.frequency.value = 330;
osc2.frequency.value = 330.2;
gain.gain.value = 0.5;

osc1.connect(gain);
osc2.connect(gain);
gain.connect(audioCtx.destination);

osc1.start();
osc2.start();
osc1.stop(audioCtx.currentTime + 20);
osc2.stop(audioCtx.currentTime + 20);