All changes to tower
| Date | Change | Source |
|---|---|---|
| 2 Aug 2016 | 1-4: frameid added; frame info added | David Sloman via e-mail |
| 4: (approx) date added | John Baldwin via database | |
| 3 Mar 2007 | Key of ring nearer A than Ab; tenor nominal added (A-52c) | George Dawson via pNBR |