So I think this is what we've used as guides:
- Tonal Harmony 4th ed. (ISBN 0-07-241570-3) lists Middle C as C4, so C4 is below A4 (page 3)
- The Science of Sound 3rd ed. (ISBN 0-8053-8565-7) lists G2 as 98 Hz, E4 as 330 Hz, F5 as 698 Hz, C8 as 4186 Hz. It also lists C4 as being below A4. This book points out that the numeric system that we're using for Octave Register is the "U.S. Standard" noting that European countries can number things differently and some organ music uses a different convention as well. (pages 756-757). In table 9.2 "Frequencies of notes in tempered scale", it shows wrapping happens between B and C. Thus B3 is 246.94 Hz, C4 is 261.63 Hz, A4 is 440.00 Hz, B4 is 493.88 Hz, and C5 is 523.25 Hz. (page 183).
- The Sound Reinforcement Handbook (ISBN 0-88188-900-8) follows the convention of The Science of Sound 3rd ed. (Figure 2-10, page 16)
- We also increment Octave Register when we go from B to C. This also corresponds to http://www.phys.unsw.edu.au/jw/notes.html.
Thanks for the detailed explanation.
I apologise if I was incorrect when referring to "conventional numbering".
It would still be very helpful to allow user-customisation of the numbering. In my scenario, I'm editing samples for mapping in Native Instruments Kontakt, where the numbering is one lower. So having consistency in numbering between this and my audio editor is important in order for the automatic mapping of samples to work.
But, as I say, your points are well-made, and taken.