let evObj = document.createEvent('Events');
              evObj.initEvent(eventType, true, false);
              element.dispatchEvent(evObj);
            }
          };
          const press = (frequency) => {
            let key = document.querySelector(`#piano [data-frequency="${frequency}"]`)
            fireEvent(key, 'mousedown');
          };
          const release = (frequency) => {
            let key = document.querySelector(`#piano [data-frequency="${frequency}"]`)
            fireEvent(key, 'mo