     <tr>
            <td colspan="2">
              Opera
            </td>
            <td>
              (HartW 1–3)
            </td>
          </tr>
          <tr>
            <td colspan="2">
              Ballet
            </td>
            <td>
              (HartW 4–9)
            </td>
          </tr>
          <tr>
            <td colspan="2">
              Incidental music
            </td>
            <td>
              (HartW 10–24)
            </td>
          </t