Polyrhythm, which exists when two or more “conflicting” rhythms sound simultaneously, creates musical ambiguity.

I can illustrate polyrhythm with a simple example of playing two against three. We begin by dividing a unit of time into six equal parts, then organizing the divisions into three-beat and two-beat groups:

1    .    .     .    .    .     (One unit of time into six divisions)

1    .    2    .    3   .     (Three beats. Count: 1 & 2 & 3 &)

1    .    .    2    .    .     (Two beats. Count: 1 & a 2 & a)

Play all three together, perhaps by tapping the single division with your feet, the triple division with your right hand, and the duple division with your left hand. Voila, polyrhythm.

For those who read music, here is a notated example of two against three.

cup of tea

Finally, here is an excellent “how to play Africa polyrhythms” video example: CK LADZEKPO – Polyrhythm from Ghana, West Africa

Polyrhythm is fundamental to the music of West Africa. Similar techniques are found all over the world.  Johannes Brahms often used polyrhythm (although he would not have called it that). 20th century Western art music is full of instances.

An interesting example of rhythmic displacement is found in Kecak, a music genre from Bali, Indonesia. You will notice in the example below that each line has the same rhythmic sequence, but because each sequence falls in a different place against the main beat (in red bold), one gets the impression of hearing altogether different rhythms.

(The letter “C” stands for the vocalization “chak.” The symbol “.” represents silence.)

C. C C . C C .  C .C C . C C .
. C . C C . C C . C . C C . C C
C . C . C C . C C. C . C C .  C

For many of my college students, the mental and emotional vitality of rhythmic ambiguity becomes immediately accessible if I change mediums and show them a bi-stable visual image, one such as the Necker Cube.


In the above image, either corner A or corner B can be visualized as projecting forward, making two perspectives from which to conceive the cube. (There is much more to notice. When looking at the image carefully, one will discover that all six cube faces can be seen as facing toward the viewer [three from each perspective]. Also, in each perspective seven corners are “visible.” And of course, when moving from conceptualizing corner A being forward to corner B being forward there is a disconcerting liminal [a transitional or neither/nor] perspective. There are many more ways to visualize this image.)

What does all this have to do with stroke rehabilitation?  I will discuss two important ideas.  First, conceptualizing and resolving ambiguity requires a certain amount of mental focus. Second, working to understand something from multiple perspectives is good practice for anyone, and especially for stroke patients.

After my own stroke, I had difficulty maintaining focus long enough to resolve ambiguity, whether it was a block of Scrabble letters, a Sudoku puzzle, or even something so “simple” as interpreting the position of hands on a clock face. (A good focusing exercise is holding a single perspective on the Necker cube. While attempting this exercise, notice the techniques employed to hold the cube in place.)

After my stroke I also had difficulty juggling multiple perspectives.  Particularly distressing was the fact that I often did not “get” witticisms.  Words seemed to carry blunt meanings rather than offer shades of nuance and possibility. In trying to mitigate the problem, I worked on conceptualizing ambiguity.

In today’s post I expected to discuss some of the melodic/tonal  exercises I use to create, explore, develop, and resolve ambiguity.  But since this post is already getting a bit long, I will wait until the next entry.

Still Here

Hi Everyone,

After a long quiet spell, I am returning to this blog and hope to maintain (at least semi-)regular contributions. I stopped posting for a variety of reasons. My basic excuse is that I was extremely busy with my job. But there were more complicated factors. As my recovery progressed, I felt increasingly vulnerable and became reluctant to share my stroke experience with the world at large. Also, I became unsure of the efficacy of my music-based recovery methodology.

For now at least, both of those issues are resolved.

Early on, my recovery seemed to progress quickly. Initially, I could not walk or move my fingers, and could barely engage in conversation. It was not long before I reclaimed those skills, at least to a serviceable level. Applying my training in music opened pathways to, and offered strategies for, rehabilitation at every level.

That said, my recovery remains far from complete. My walk is uneven, fingers are difficult to control, and conversation can be nerve-wracking. (I am stating facts, not complaining.) Casual observers tell me they perceive no deficits. Either they are trying to be supportive or not looking carefully.

Four-and-one-half years after the big event, I continue to improve, albeit slowly.

I began this post with the reasons why I stopped blogging. I close by stating why I am starting again. One reason is a desire to continue sharing my experience in the hope that it may be of value to others. Another one is relatively self-centered. Writing this blog requires energy, discipline, and tenacity. It develops my organizational skills and, most importantly, sparks rich levels of introspection. In the past, writing this blog was a therapeutic act. I hope it will be so again in the future.


Song Therapy

Many of the stroke patients with whom I recently have been visiting suffer from aphasia ranging from slight to severe.

One patient with whom I have visited regularly for the past month had said nothing whatsoever until about 10 days ago, when s/he said a single word so softly I had to get really close to hear it at all. Last Tuesday, s/he greeted me by singing consonants in a full voice. Each consonant on a different pitch, the sum of which added up to a three-syllable word.

S/he taught me the song, which we sang together.

Incredibly cool.

On Thursday, s/he demonstrated movement in both afflicted arm and leg. Another first.


This blog recently received a bunch of hits from England. It turns out that four graduate students/speech and language therapists at City University London are doing a project titled, “Blog talk: the impact of aphasia on people’s lives.”

I have mixed feelings on being deservedly selected as one of their subjects.

That said, two days ago I pulled my dictaphone. When I tried to put some music on it, I discovered the flash drive was full.  So, I began erasing old stuff. But not without first listening to it. I came across material dictated while at Spaulding Rehabilitation Hospital in the first weeks after my stroke. It was shocking to hear how I struggled to speak.  Many multi-syllable words were landmines. They tended to explode halfway through and required multiple attempts to articulate.  If I tried to say a verb ending in ‘d’ in the past tense (‘tend’ to ‘tended’), the diction was either mush (‘tendehthh’) or expansive (‘tendededed’).

During the past few weeks, I have been visiting with some stroke patients who have lost all speech. I stay and talk as long as they seem interested, and a long as I can think of optimistic things to say.

Sounds of Silence?

In a 2010 article, my father-in-law et al. noted that, “Diseases like osteoarthritis are highly symptomatic (or ‘noisy’) conditions that provide cues for monitoring [and treatment, whereas diseases] like hypertension and hyperglycemia are relatively ‘silent,’ or asymptomatic.”* The “silent” diseases are particularly insidious, because they are so easily ignored.

Stroke is slippery. It seems to fit in both categories. On the one hand, the effects are “noisy” (constant and pervasive). But on the other hand, once one is resigned to disability (even when living with acute deficits), the effects become routine. The experience of them seems to retreat towards the “silence” of resignation.

Stroke recovery requires tenacity, in my case at least. This seems to be even more so at relatively advanced stages of recovery. Five weeks after my 10/11/09 stroke, I could safely get around my home without a cane. Eight months after my stroke my wife and I spent a day hiking in the Chilean Andes. But even now, my balance is poor. Unless I totally focus on my coordination, I have a noticeable glitch in my walking step. I suspect resolution will transpire only if I work to keep my deficits “noisy.”

*Handbook of Behavioral Medicine Methods and Applications. Andrew Steptoe, Editor. 2010.

Depression Impression

Today’s post is inspired by an article I just read: “Poststroke Depression: An Examination of the Literature” (1997). It’s not the catchiest title, but the piece got me thinking.  As the colleague who sent it to me noted, the paper “illustrates the flaws in the conceptualization and assessment of [poststroke] depression, basically the failure to distinguish the components of depression (mood; somatic symptoms; self critical symptoms) and their differing origins (somatic may be symptoms of stroke, not depression) and different consequences.” I agree, but the real elephant in the room is that the scholarly literature undervalues, even ignores, the character of the stroke patient’s inner life.

One of my more frustrating experiences, especially during the early stages of my recovery, was caregivers treating my cognitive condition in a mechanical fashion, like so many broken bones needing to be set.  In my experience, assessing a patient only in terms of deficits (as scaled against unattainable social norms) undermines self confidence, undermines the powers of self observation, and diminishes agency. (All of which can be plenty depressing.)

Yes, of course, I needed to find a way to heal if I was going to function successfully in the workaday world. In that, the caregivers were 100% correct. But my inner reality (though marked by perceptual idiosyncrasies, conceptual roadblocks, and expressive stasis) felt remarkably rich. It shouted for my attention. These cognitive experiences were once in a lifetime (I HOPE), but my caregivers seemed to consider them of no value. Consequently, I felt pressure to devalue them as well.

Happily, I resisted. My stroke experience taught me to pay deeper attention to (and place higher value on) my thinking processes. This constituted an important step in taking an objective measure of my place in the world.


I continue to visit stroke patients. Most stay in the facility three to four weeks, which is long enough for them to make dramatic improvement. It is magical to witness recoveries unfold.

I sometimes get to know patients quite well. They tell me stories about their lives and families, and also of their hopes and fears. (Social pretense tends to be low, even non-existent.) I am happy to share most anything, but mostly they want to know about how I dealt with my stroke and managed my recovery.

I have made good friends (indeed, friends for life), but do not expect to see them again. Relationships conceived under sorrow’s inward journey are different from those built amidst joy’s effervescence.

Last week, a number of patients with whom I had come to feel quite close were discharged for home or to step-down facilities. All had left before I arrived. They were thrilled to move on, of course. But to me, the ward felt quite lonely.

Good Vibes

There is a lovely park a few blocks from our house. It has a few playing fields, but the land is mostly woods and trails. I walk there with our dogs almost daily.

It rained much of yesterday. During the night, rain cooled to snow.

It had stopped snowing by the time we got into the woods, and a  magical “inside-out” light seemed to emanate upward into the gray predawn sky. Since the dogs had run ahead, all was still. Mostly still… Spring is coming and the birds are singing it in.

Lately, I have been studying Goethe’s color theory, which this morning got me thinking of nature’s light mandalas (not Goethe’s word).

In the stillness, I could almost hear them.

That intuition brought me to German physicist and acoustician Ernst Chladni (1756-1827), best remembered for his studies of the acoustical properties of metal plates. Chladni found that plates vibrate in symmetrical geometric patterns that change in accordance to the overtone series.

Where else does one find Chladnic-like figures? Might one conceptualize snowflake geometries as frozen motion? Is frost on a window pane the hidden made visible?  What about plant symmetries?

What about nature as a whole? Does all life on Earth dance to sunlight’s vitalizing tones?

If we stop making so much noise, perhaps we will hear the music.


Backyard. Just before 8 a.m.

Taking Stock

For the past months I have had difficulty writing this blog. Here are some of the reasons:

  1. Although I still have a lot to say, I am increasingly unsure of how best to say it.
  2. As my recovery continues, I am becoming more private. I am less comfortable sharing my daily thoughts and struggles.
  3. Acting upon my therapeutic insights once produced dramatic and nearly immediate improvement. Now, because results tend to unfold slowly, I have less to report. 
  4.  Recovery from a massive stroke takes much longer than I expected. I remain tenacious in my therapeutic efforts, but confidence has been shaken.
  5. The more time I take between blogs, the more pressure I feel to write something insightful. (This post ignores that issue.)

Going Digital

Yesterday, I  taught a West African dance in one of my classes. For efficiency, I demonstrated the movements while clapping the timeline and singing the drum calls. At one point, when the dance required lifting both hands over my head, one of the students yelled out to his colleagues to make sure they wriggle their fingers.

Wriggle the fingers?


I looked up and saw my stroke-side fingers moving in every conceivable way. All the brain activity had put my digits in full motion.

In fact, these fingers have been restless as of late. They often twitch when I am engaged in a right-hand activity. Sometimes they twitch when I try to go to sleep. My thumb sometimes misfires when I practice piano.

I mostly think that this is an excellent development. Having few crossed wires is far better than no wiring at all.