renderNote = (value, idx) => {
const div = html`<div>${scale[idx]}</div>`;
div.style.backgroundColor = `rgba(0,${Math.round(255 * value)},0,1)`;
div.style.textAlign = "center";
div.style.float = "left";
div.style.width = "2.5em";
div.style.border = "1px solid #333";
return div;
}