| In the early years of the seventeenth century, English composers increasingly turned to the hexachord as a cantus firmus for keyboard pieces. |
| When copying Monteverdi's Ahi dolente partita on pp.410-11, each occurrence of a unison between the two cantus parts is marked with a cross. |
| The use of a plainchant cantus firmus, or dominating tenor theme, knit together the movements even though they were separated during the liturgy. |
| To cantus firmus a write two counterpoints above and two below in the first species. |
| But Farmer's cantus part had no independent existence, and certainly would not have been used for congregational singing. |
| The cantus firmus is sounded in semibreves in the middle of the three voices. |
