[pianotech] "Stealth" temperaments

[Ron Koval]

I thought a few of you may be interested in trying something that I've been working on for some time. Many thanks over the years to those that got me interested in tonal temperaments and helped first with understanding, then with the creation of new temperaments - Bill Bremmer, Ed Foote, Paul Bailey, Robert Wendell, Jason Kanter and David Bauguess, to name a few.
I've spent the last few years working on "stealth" temperaments, those tonal tunings that have just a bit of key color without being strong enough to give anyone the "heebie jeebies"...
At www.rollingball.com, my Koval Variable temperament is graphed at a few strengths - the basis for today's post.  I wanted to make a temperament with the most variety with the smallest offsets.  The naming number represents the largest offset - shared by both C and F.  There may have been some tweaks since the graphs, so the numbers may not quite match.  What I've found is that there are four "strengths" of this temperament that fall under the mild Victorian style; two of which can safely be used in all situations.  The stronger ones are still very mild, but there is extra vibrancy in some of the remote keys, though still much milder than the EBVTIII.  These are good places to begin your journey, as well as your ear training to feel the difference of the thirds progression.  These are the four strengths that are different enough to make a difference, yet not too far apart - they make a nice progression.  
KV 1.15KV 1.3KV 1.7KV 2.1
So the largest offset from ET ranges from 1.12 cents to 2.1 cents.  It surprised me how little change in cents could be felt both "from the bench" as well as from the audience.  
KV 1.15A 0A# .99B -.57C 1.15C# -.15D .46D# .69E -.46F 1.15F# -.31G .76G# .31Major thirds 12.1-15.0   ET thirds = 13.7 
KV1.3A 0A# 1.13B -.65C 1.3C# -.17D .52D# .78E -.52F 1.3F# -.35G .87G# .35Major thirds 11.9-15.2
KV 1.7A 0A# 1.48B -.85C 1.7C# -.22D .68D# 1.02E -.68F 1.7F# -.46G 1.14G# .46Major thirds 11.3-15.6
KV 2.1A 0A# 1.82B -1.05C 2.1C# -.28D .84D# 1.26E -.84F 2.1F# -.56G 1.4G# .56Major thirds 10.7-16.1
There are stronger choices, but these offer a 'safe' place to begin a temperament journey...
Ron Koval