Saturday, March 31, 2018

An unusual 22 tone 7- limit tuning

Today's puzzle is 7 limit 22 tone scale based on a 1 9 15 35 set where the result in the lattice finds each factor is two simple ratio steps from each other. The center tetrad of 0. 3. 4. 20. in 22 tone step units is a 'tetrad' within a hexany whose outer points form two diamonds. The chart in the up left corner reflects Wilson interest in transforming a structure in a given tuning by multiplying the unit sizes, here limited to odd numbers in 22. The choice of units might reflect the all interval sets found in 13 here embedded in 22 as two interlocking diamonds.

Sunday, December 11, 2016


Invited are all memories and/or comments in tribute to Erv Wilson. Please post your own recollections below or just share your thoughts in memory of this man.

Wednesday, June 8, 2016


This 22 tone scale of Wilson's believed to be from 1967 was found in a series of papers, charts and scales based  stellating Hexanies in  i have not seen before. One particular method resulted in the example below which seems to form the core of the scale above. Wilson took the 1-3-7-11 hexany and stellated it with 5 and /5 to complete the 8 basic triads found within which results in the 14 tone structure to the left. The result of this type of stellation has unexpected results. for instance 4 other hexanies are formed each which occurs twice.  All involve the added 5 plus three factors of the 1,3,7,11 set.  Because of the relationship of most of the added pitches to this stellate being 3/2 above and below, to form this 22 tone scale. 4 more hexanies also appear. The result is one of many 22 tone scales that contain a great variety of compact hexany subsets. 

Tuesday, March 1, 2016


This is an unlabelled set of pentatonic scales in rotation in what first appeared to be a process similar to that used in his Purvi papers but was not in the end. Adjacent pages carry the year 1982. This set of 5 limit scales he has mapped over 53 squares with the whole set comprising 17 different pitches. In 53 unit sizes would be 53232323-53232323-9 implying two tetrachordal like blocks of 4/3 repeated with a 9/8 disjunction. Each interval shift involve the difference of a 25/24. The paper deserves more more attention. Comments and observations are welcome on this one.

Wednesday, August 12, 2015


In this document novavotreediamond.pdf an inspection reveals that the sequence of notes is determined by common tone modulations of the top hexad. That is by shifting the hexad over one place at a time similar to going through the modes on a common tonic, a 23- note diamond like structure results illustrated at the bottom.

The Lone Page Showing a Unique 7 limit Diamond.  The Centerpiece of a File Now illustrating a Diamond Formed From the Scale tree or the Mt. Meru Triangle 

What is unusual is the choice of 6 notes that make up the seed to the process. It turns out this hexad is formed by the scale tree section seeded by 1/1 and 2/1 shown on page 2 and borrowed from another document. This section of the tree was the focus of Novaro who also played with some triangles that do not repeat at the octave mention in this blog in the past. so i have added an example of what type of result we can expect from that process. Here instead of using the tree  a reseeding of the meru triangle is used to show another way one can visualize the sequence. What occurs in on the other side of the 2/1 differs only by commas with the lower set of pitches. This could be used as possibly a layout where one only has rooom for centain notes in each traditional octave space.

What should not be lost is the unique type of diamond presented here. It is  neither a harmonically or melodically based one, but one that is formed by the tree or a descent down Mt. Meru triangle.

Friday, July 10, 2015


Consider Olympos is a preliminary paper to The Marwa Permutations and augments some details that might not be clear in general. First that a generator of a scale can be thought to be a variable within set limits and also shows how the chain can be used as a sequence to generate larger scales. 
Page one of Consider Olympos-a draft of a paper that would become his Marwa Permutations 

Friday, January 9, 2015


The Most Common Generalised Lattice used by Wilson.
It is hard to think of a microtonal theorist who has made more headway with developing lattices than Erv Wilson. Here the concentration will be on what he nicknamed  an “Euler“ lattice after where he drew his inspiration.
By working with a template where each prime harmonic has a unique spacing , he managed to avoid clashes when generating lattice of multidimensional harmonically-based structure

There are some other features worth pointing out.  For instance harmonically generated intervals will always appear above the fundamental and the subharmonics below. With a  9-limit system the direction will be both above and to the right , leaving the other quadrant for more complex ratios with the opposite with the subharmonic. This makes it quite easy to understand what is being represented.

Commonly he would use a 10 square to the inch graph paper which explains why he didn’t use a template where all the numbers where divided by 2. This way he had room to notate both ratios and often the scale degree. The latter always followed by a period or dot to separate it from the ratios.

Lately i have been using the following lattice which seems to overcome a few trouble spots. This was plotted using 20 squares per inch.
Alternative lattice by Kraig Grady in cases of slashes with Wilson's Lattice.