What is “Mapping”?
WHEN we have practiced good actions awhile, they become easy; when they become easy, we take pleasure in them; when they please us, we do them frequently; and then, by frequency of act, they grow into a habit. –Tillotson
Mapping is similar to setting the temperament in aural-only tuning.
The Mapping routine involves mapping and tuning all the A’s on the piano.
In addition to all the A’s:
The mapping of A3 involves the tuning and mapping of D4 & E4.
Mapping A2 involves mapping and tuning D3, & E3.
E1 is used for mapping A0.
Mapping A5 involves mapping and tuning D5 & E5,
Mapping A6 involves mapping and tuning D6 & E6.
The number of notes tuned and mapped here is very similar to what is often done with aural-only tuning. But, an aural-only temperament is contained only in the middle of the keyboard.
With the mapping and tuning of these 17 or so notes across the entire keyboard, the overall sound of the whole piano can be heard. As the mapping is done, all the previously mapped notes are used as references.
Just like with an aural-only temperament, the rest of the mapping (and tuning) evolves from the prime octave mapping.
Both mapping and aural-only tuning put the Tuner/Technician in complete control of how the piano will sound.
Once the mapping is complete, the LC spreadsheet can easily fill in the chromatic notes between all the targets.
Mapping begins @ A4.
As in aural-only tuning, mapping begins with the placement of A4.
The most important and the most difficult note to map, is A3. But just like setting the temperament in aural-only tuning that’s where it must start, and that’s one of the reasons why we call it the ‘Prime’ Octave.
Instead of tuning all the notes in a ‘temperament’ octave, we are going to map just four: A3, D4, E4 and A4 of the prime octave. Mapping those four notes is the most difficult routine in the whole mapping process.
Mapping A3 is done with templates. Templates are used because they make it easy to try different A3/A4 widths. Once a template has been selected for mapping A3, D4, and E4 are tuned using the templates as well.
Once D4 and E4 are tuned, the prime 5ths can be tuned measured. The widths of the prime 5ths (A3/E4 & D4/A4 – more on them here) are used to establish the width of the prime octave. The widths of the prime 5ths let us know if the prime octave is too wide or too narrow.
If the prime 5ths indicate the octave width needs to be adjusted, a different template with a higher or lower A3 setting is selected. Then A3, D4, and E4 are re-tuned and the prime 5ths re-measured to see if the template is a better prime octave width for the piano.
Once the octave width is correct the 5ths need to be balanced so they are both about the same width.
Balancing the prime 5ths involves adjusting the mid point in the template’s A3/A4 curve – raising it up or down – so the 5ths are the same width. Again, all of that is done with templates.
Once all of this is done, the targets settings for A3, D4 and E4 are known.
Once the prime octave has been established, mapping both above and below the prime octave is fairly straightforward.
It’s really up to the technician as to how each target note is found, but once it’s location is known, it must be measured using the right partial – the partials that are recognized by the LC Spreadsheet.
The LC Spreadsheet’s partial arrangement uses the 4th partials from A0 – A4 and the fundamentals (1st partials) from A#4 – C8.
Even though every target note can be found using aural-only tuning, mapping is best done using a combination of aural and technical skills to find each target. A well mapped target will confirm both methods. Or maybe better said would have been both methods will confirm a well mapped target.
Once the mapping has been completed and all the the target note settings have been entered into the spreadsheet, a tuning can be created by the Tuner/Technician, imported into a Sanderson Accu-Tuner, and then used for the tuning.