<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8"/>
<title>3D Music sequencer</title>
<script>
const ROWS = 8; // total number of rows
const COLS = 16; // total number of columns
const CELLSIZE = 50; // size of each cell in pixels

const COLORS = [“#ff0000”, “#00ff00”, “#0000ff”, “#ffff00”, “#ff00ff”, “#00ffff”, “#cccccc”, “#ffffff”]; // available colors for cells

let drums = []; // array to hold 3D drum sequencer data
let selectedColor = “#ff0000”; // default selected color

// initialize the 3D drum sequencer with empty cells
function init() {
for (let i = 0; i < ROWS; i++) {
let row = [];
for (let j = 0; j < COLS; j++) {
let col = [];
for (let k = 0; k <= 3; k++) {
col.push(false);
}
row.push(col);
}
drums.push(row);
}
}

// draw the 3D drum sequencer on the canvas
function draw() {
let canvas = document.getElementById(“canvas”);
let ctx = canvas.getContext(“2d”);

// clear the canvas
ctx.clearRect(0, 0, canvas.width, canvas.height);

// draw the cells
for (let i = 0; i < ROWS; i++) {
for (let j = 0; j < COLS; j++) {
for (let k = 0; k <= 3; k++) {
if (drums[i][j][k]) {
ctx.fillStyle = COLORS[k];
ctx.fillRect(j * CELLSIZE, k * CELLSIZE + i * CELLSIZE, CELLSIZE, CELLSIZE);
}
}
}
}

// draw grid lines
ctx.strokeStyle = “black”;
for (let i = 0; i <= ROWS; i++) {
ctx.beginPath();
ctx.moveTo(0, i * CELLSIZE);
ctx.lineTo(COLS * CELLSIZE, i * CELLSIZE);
ctx.stroke();
}
for (let j = 0; j <= COLS; j++) {
ctx.beginPath();
ctx.moveTo(j * CELLSIZE, 0);
ctx.lineTo(j * CELLSIZE, ROWS * CELLSIZE);
ctx.stroke();
}
}

// update the selected color
function setColor(color) {
selectedColor = color;
}

// handle cell clicks
function handleClick(event) {
let cellX = Math.floor(event.offsetX / CELLSIZE);
let cellY = Math.floor(event.offsetY / CELLSIZE);
for (let k = 0; k <= 3; k++) {
if (drums[cellY][cellX][k] && COLORS[k] == selectedColor) {
drums[cellY][cellX][k] = false; // remove cell
} else if (!drums[cellY][cellX][k] && COLORS[k] == selectedColor) {
drums[cellY][cellX][k] = true; // add cell
}
}
draw(); // redraw canvas
}

// add event listeners
function addListeners() {
// handle color clicks
let colorButtons = document.getElementsByClassName(“color-button”);
for (let i = 0; i < colorButtons.length; i++) {
colorButtons[i].addEventListener(“click”, function() {
setColor(COLORS[i]);
});
}

// handle cell clicks
let canvas = document.getElementById(“canvas”);
canvas.addEventListener(“click”, handleClick);
}

// start the sequencer
function start() {
let beat = 0;
setInterval(function() {
// play the drums for the current beat
for (let i = 0; i < ROWS; i++) {
for (let j = 0; j < COLS; j++) {
for (let k = 0; k <= 3; k++) {
if (drums[i][j][k] && k == beat) {
let audio = new Audio(“drum-” + k + “.mp3”);
audio.play();
}
}
}
}
// update the beat counter
beat++;
if (beat > 3) {
beat = 0;
}
}, 400); // 400 milliseconds per beat
}

// initialize, draw, and add event listeners to the sequencer
function main() {
init();
draw();
addListeners();
}

// start the sequencer when the page is loaded
window.onload = function() {
main();
start();
};
</script>
<style>
canvas {
border: 1px solid black;
}
.color-button {
width: 30px;
height: 30px;
border-radius: 15px;
margin-right: 10px;
cursor: pointer;
display: inline-block;
}
.color-button:hover {
transform: scale(1.2);
}
</style>
</head>
<body>
<h1>3D Music sequencer</h1>
<canvas id=“canvas” width=“800” height=“400”></canvas>
<br/>
<div>
Colors:
<div class=“color-button” style=“background-color: #ff0000;”></div>
<div class=“color-button” style=“background-color: #00ff00;”></div>
<div class=“color-button” style=“background-color: #0000ff;”></div>
<div class=“color-button” style=“background-color: #ffff00;”></div>
<div class=“color-button” style=“background-color: #ff00ff;”></div>
<div class=“color-button” style=“background-color: #00ffff;”></div>
<div class=“color-button” style=“background-color: #cccccc;”></div>
<div class=“color-button” style=“background-color: #ffffff;”></div>
</div>
<script src=“script.js”></script>
</body>
</html>

script.js: