| 1450 | Building of a great organ |
| 1482 | Rebuilding of the existing Gothic organ, presumably by Johan then Damme (with Rudolf Agricola as his adviser) |
| 1542 | Alteration in Renaissance style |
| 1564 | Enlargement by Andreas de Mare |
| 1627-28 | Enlargement by Anthoni and Adam Verbeeck |
| 1685-90 | Alteration by Jan Helman |
| 1691-92 | Rebuilding and enlargement (32'-pedal towers) by Arp Schnitger |
| 1728-30 | Alteration and enlargement (new Rugpositief) by Frans Caspar Schnitger and Albertus Anthonie Hinsz |
| 1740 | Large-scale repairs after subsidence, and enlargement with seven new stops by Hinsz |
| 1808-1912 | Numerous modifications by Lohman, van Oeckelen and Doornbos |
| 1938-39 | Alteration (electrical action and re-voicing) by J. de Kof |
| 1971 | Disassembly because of restoration |
| 1976-84 | Restoration, partial reconstruction by Jürgen Ahrend from Leer/Loga (based on the 1740 situation). Adviser was Cor H. Edskes. |
