Month: February 2012

CatSynth video: PHOENIX – Love Like A Sunset Sound (nearly)

By KidsAtMidnight on YouTube, via matrixsynth.

PHOENIX – Love Like A Sunset Sound (nearly)

Was supposed to be working on new track (and feeding the cat) but got sidetracked by the MoogerFoogers. Found a sound a bit like the mad glissando CS80 at the start of Love Like A Sunset so tried to work out the part a bit. Stole the Marimba-like bit from the Multitrack they put online.

Arthur (cat) was just hungry and attention seeking. He’s not normally too bad a chewer. Mind you, I did find all but one knob from my Digi002 in the hallway once. Bad boy …

Reconnaissance Fly in January, with Luke Westbrook, Grex and Greenlief/Dykstra/Perkis

Today we look back at two Reconnaissance Fly performances in early January. The first was a return to Luna’s Cafe in Sacramento, and the second was at Revolution Cafe in West Oakland. By coincidence, we shared the bill on both nights with guitarist Luke Westbrook who was visiting from New York.

This was Reconnaissance Fly’s third gig at Luna’s – we like playing there and not just because it shares my cat’s name. But the stage was once again a bit cozy for a band of our size, even more so now that we have a fifth member, Chris Broderick on reeds (saxophone, clarinet, bass clarinet). This was our first public performance with the new quintet lineup. So it was a bit of puzzle trying to get the bass, drums, keyboard and bass flute on the stage, and still find room for the people who play them. But somehow we managed.


[Photo by Tom Djll]

Our set went well – at least, I was pretty happy with it. Our opening graphical score improvisation piece Small Chinese Gong went off without a hitch. As Neat As Wax is becoming our most consistently well-played song, as it is not too difficult and it is quite lyrical and rhythmic. Electric Rock Like a Cat and Sanse Iz Crede Nza are our most difficult, but also the most energetic and got a great response from the small but enthusiastic audience when we hit the final notes.

After striking the stage, it was time to relax with beer and guacamole and other treats and enjoy the next sets. Luke Westbrook took the stage for a solo guitar performance.

He has a very intense stage presence and a virtuosic technique, but the music itself has a certain ease to it. It began with gentle arpeggios that had a consistency even as they were constantly changing. These evolved into more defined repeated phrases over time that were occasionally punctuated by the occasional chromatic tone or blues-like bend. Later on, the music become more distorted with noisier and more percussive elements. There was a passage of single repeated tones that provided an increasingly anxious vibe before settling down again.

Westbrook was followed by Philip Greenlief and Jorrit Dykstra on saxophones with Tim Perkis on electronics. On the things I look for in electro-acoustic combos is how well the electronic and acoustic parts blend. In the case of this trio, they blended quite seamlessly from the start with long tones of subtly different intonation. The music soon became more animated, with syncopated saxophone rhythms set against low gurgly electronic sounds.

There were many humorous moments with matching squeaks and bleats, and richly textured moments with multiphonics against electronic pads. Perhaps the most amazing moment of the entire set was a long virtuoso noise solo by Dykstra. It is hard to describe in text, but it was one of the most impressive saxophone performances I have heard in a while. The later sections of the performance featured more percussive saxophone sounds, key clicks and striking of the metal hardware set against contrasting electronics with vocal and wah-wah effects.

Revolution Cafe is located deep in West Oakland, not far from the rebuilt I-880 freeway, which makes for an interesting exterior environment. The interior is something altogether different, with every surface adorned with vintage and eclectic artifacts. There were street and highway signs, political posters (from old Oakland Mayoral elections to the most recent Jean Quan recall announcements), vintage keyboard instruments, strange dolls and even a shrine of sorts of Frank Zappa. I spent quite a bit of time just photographing the space before even considering the music.



[Click images to enlarge]

The show was actually the latest incarnation of Karl Evanglista’s Light A Fire series. I had performed in this series last year with solo electronics. This even opened with another solo guitar set by Luke Westbrook.

Westbook’s performance was actually quite different from the one he did two night’s earlier. While his technique was on display both nights, this one was more virtuosic and more diverse in terms of material and sound. This performance was mesmerizing. I had a sense of warmer colors as he played, though that may have been a kinesthetic combination of the cafe’s ambience and Westbrook’s harmonies.

Next up was Grex, the duo of Karl Evangelista on guitar and Rei Scampavia on keyboard, voice and flute. Their music covered quite a bit of range, some more song-like with voice, keyboard and guitar, some closer to free-jazz with fast-moving improvised lines. One memorable moment featured featured a mellow guitar solo – Evangelista is quite a versatile guitarist – that morphed into in a driving loop pattern with distortion that produced its own harmony.


[Click image to enlarge]

I believe at least some of the material was from Grex’s recently release CD. You can follow the link above to find out more info.

Finally, it was our turn to take the stage. I had toyed with the idea of using the Cafe’s B3 for An Empty Rectangle, but in the end decided it would have been a lot of effort, especially with a stage that seemed to be even smaller than Luna’s Cafe We had a lot of fun and played with a lot of energy that matched the intensity of Revolution Cafe’s decor. It didn’t feel as tight or accurate as we would want for a Reconnaissance Fly set, but it did have the humor that has become part of our band’s character.

Additionally, the visuals of the space and the presence of the old keyboard instruments did inspire me to consider a future solo performance or installation there. I don’t have much more to say about that yet given everything else that is going on this season, but something to consider for later…

Carnival of the Cats #414

We at CatSynth are happy to host Carnival of the Cats #414!

The Carnival of the Cats occurs every Sunday and features feline-themed posts submitted from around the “blogosphere.”  You can participate by leaving a comment or using the handy submission form.  Although we are questioning the handiness of the submission form this week, as we have very few participants.  But we’re here for those who are participating, so let us get started.

Elvira turned two years old this past week. Please join us in wishing her a happy birthday!  It looks like she had a good celebration with her family.  Her birthday week also happened to coincide with Valentine’s Day.

Meanwhile, Nikita relates his dad’s recent acquisition of cat-themed books.  It looks like they have quite a collection going, including some vintage books from the 1940s and 1950s. [Note: it is actually Elvira in the photo above.]  It reminds us at CatSynth that we should do a similar post one of these days.

In addition to hosting this carnival, we did a photo of Luna for the Weekly Photo Hunt on the theme of “point”, along with a pointing maneki neko. We encourage visitors to check it out.  There is a highway sign as well (yes, we’re a little odd).

It’s Flash Back Sunday at Life from A Cat’s Perspective, with significant pictures from the past, including one of the last with Samantha and Mr. Tigger together. They all miss him very much.

Over at Sweet Purrfections, Truffle and Brulee claimed this bed as their own and are enjoying a nap on it. I think they match the bed and the room quite nicely.

Jill of BabyBakes introduces Chuck (aka “Kat”), a new kitten. She relates the story of how this tiny kitten came into their lives, and also the adventures of putting together a new “kat tree.”

At Animal Shelter Volunteer, Moosey knows exactly how to spend a Sunday: enjoy a nap in a patch of sunshine. He looks quite comfy and relaxed there.

Intermezzo on Water

Intermezzo on Water

The words and sentences float losing their coherence as the visions and narratives of seaside communities decay into dreams of filtered sunlight and free verse and fog and failed concentration and ambiguous affections and terraced layers of improbable houses and the percussion and the solitude and concrete ruins washing into the ocean.

From the dissolving darkness a faint buzzing punctuated by clicks spirals outward along silent waves. In its wake sparks radiate and melt into the meandering trail of a melancholy story.

[Originally written September 15, 2003]

Weekend Cat Blogging and Photo Hunt: Point

There are so many interesting ways that one can interpret this week’s Photo Hunt theme of Point. Mathematics and highways come to mind, but this is of course also Weekend Cat Blogging, so as usual we feature cats. First, one of our many maneki nekos points its paw:

And here is Luna pointing while basking in the morning sun:

Both of these photos were taken with the latest lens and film options I got for the Hipstamatic app on the iPhone.

Another Hipstamatic photo on the theme does veer into the realm of highways. Here is one of several studies I did with the freeway entrance shield for the Bay Area’s infamous Interstate 238 for an upcoming article on the highway. It has the customary downward pointing arrow of freeway entrances in California.

Tomorrow (Sunday), we at CatSynth will be hosting the weekly Carnival of the Cats. If you have a feline-themed blog post from the past week, you are welcome to participate. Just visit the handy BlogCarnival submission form or leave a comment below.

Weekend Cat Blogging #350 is hosted by Kashim, Othello and Salome.

The Weekly Photo hunt theme is Point.

As stated above, we are hosting the Carnival of the Cats tomorrow.

And the Friday Ark is at the modulator.

Ackermann’s Function and “Really Big Numbers”

Today we return to to the topic of mathematics with a look at Ackermann’s Function. Anyone who has studied computer science has probably encountered this function (though I’m sure many have gone on to forget it). It is most commonly defined as follows:

This is actually a variant of Wilhelm Ackermann’s original function, often called the Ackermann–Péter function. It is quite a simple function to define and to trace, and it is very easy to implement in just about any programming language, including Python:

def ackermann(m, n):
  if m == 0:
    return n + 1
  elif n == 0:
    return ackermann(m - 1, 1)
  else:
    return ackermann(m - 1, ackermann(m, n - 1))

However, its complexity (in terms of run-time and memory) grows quite quickly. As such, it is often used as an exercise in teaching students more complex forms of recursion, and also as a test case in compiler development for optimizing recursion. It also has some interesting mathematical properties for particular values of m:

The numbers in the case of A(4,n) are quite large. Indeed, one could describe Ackermann’s function as “computing really really large numbers really really slowly.” Although the numbers grow quickly, the function is really just doing subtraction and recursion. We can take advantage of the properties described above, however, to make some shortcuts that yield a much more efficient function.

def ackermann(m, n):
  while m >= 4:
    if n == 0:
      n = 1
    else:
      n = ackermann(m, n - 1)
    m -= 1
  if m == 3:
    return 2 ** ( n + 3) - 3
  elif m == 2:
    return 2 * n + 3
  elif m == 1:
    return n + 2
  else: # m == 0
    return n + 1

With this version computing A(m,n) for m≤3 becomes trivial. And this makes computations for m≥4 possible. Or at least A(4,2), which we can actually run in python to reveal the 19,000 digit answer.

You can see the full value on this page. Computing A(4,3) is infeasible. Even with the optimizations, most computers will run out of memory trying to compute this value. But one can still reason about these rather large numbers. Let us move from the more common function we have been using to Ackermann’s original version:

This version has three arguments instead of two, and on the surface it may seem a bit more complicated. However, different values of the third argument p yield very familiar operations.


Again, this function is a rather inefficient way to compute addition, multiplication and exponentiation, but it is an interesting way to reason about them and extrapolate to other more exotic operations. For example, if we take p to be 3, we get the following operation.

Just as m x n is adding m to itself n times, and exponentiation mn is multiplying m by itself n times, this new operation (sometimes called tetration) is the next level: exponentiating m by itself n times.

Such an operation grows so fast as to be uncomparable to exponential growth. It grows even too fast to compare to the gamma function which have explored on CatSynth in the past. This series of ever higher-order operations is often noted with an arrow, called Knuth’s up-arrow notation after legendary computer scientist Donald Knuth.

Using this notation, we can define as sequence of numbers, called Akermann Numbers, where each is an ever higher-order operation of the element applied to itself.

  • 1↑1 = 11 = 1,
  • 2↑↑2 = 2↑2 = 22 = 4,
  • 3↑↑↑3 = 3↑↑3↑↑3 = 3↑↑(3↑3↑3) = 

Even just the 4th number is this sequence is so large that we can’t even easily notate it with exponents. So forget about the 5th number in sequence. But a question that interests me is what about interpolating with real numbers. What is the 1 1/2th Ackermann number? That question, if it even has an answer, will have to wait for another time.

CatSynth video: The Scanimate

Moog Little Phatty and the Scanimate

From experimentalsynth on YouTube, via matrixsynth where you can read more and see more images. A cute black cat makes a cameo appearance during the video 🙂

“The first attempt at controlling analog video animation with control voltage created by a Moog synthesizer. Learn more at www.scanimate.com and www.experimentalsynth.com”

“Scanimate is a 100% analog video animation system in use form the late 60s to early 80s. It was used on a number of popular films & TV shows including, Star Wars, Logan’s Run, Sesame Street & NBC Sports. Only eight were built and they originally sold for around $1,000,000.”

It’s interesting to consider in the context of the recently released LZX analog video modular synthesizer.

Gino Robair and Andrea Centazzo, with Trevor Dunn and Travis Laplante, Luggage Store Gallery

The first Thursday of this month featured an impressive performance by Andrea Centazzo together with Gino Robair at the Luggage Store Gallery in San Francisco. I had missed an earlier performance of theirs at another Bay Area venue earlier the week, but glad I was able to make this one.

The evening opened with solo sets by Trevor Dunn on upright bass and Travis Laplante on saxophone. Dunn’s set unfolded as a single piece, which had just started when I arrived. It was a combination of long bowed notes that are part of traditional bass practice along with timbral effects and more percussive extended techniques. The low tones filled the room nicely and provided a more meditative start to the evening.

Laplante’s solo saxophone set was quite a contrast in terms of energy and dynamics. It was nearly all extended technique with fast runs of notes. And it was quite loud. Given the acoustically active nature of the Luggage Store Gallery, this made for some interesting effects. I think the combination of the two sets worked well. Dunn and Laplante were touring the west coast of the United States and Canada together, so I suspect their contrasting styles played into their other performances as well.

Afterwards, the audience shifted 90 degrees towards the front of the gallery, where two tables festooned with a variety of percussion and electronic gear awaited the start of the second set. Andrea Centazzo’s table was dominated by the MalletKAT, a marimba-like electronic controller.

He also had a variety of small acoustic percussion, as well as this toy that he said was from a previous visit to San Francisco in the 1980s.

Gino Robair had his usual assortment of percussion, noisemakers and electronics, including the Blippo Box and his signature broken cymbals.

The set began in either a dramatic fashion, nor in an especially subtle way. It was well timed and well balanced and drew one quickly into the music. As I have said on previous occasions, a masterly improvisation performance will balance rhythm, dynamics and timbres into a cohesive whole, and this performance was no exception. Even with the “noisy” source instrumentation, I felt like the interaction of the performers created a harmonic structure of sorts to go along with the rhythms. And the electronic and acoustic elements blended well in this context. You can hear a short excerpt in this video:

Overall, this was a great performance, and I sat quietly and intently in full absorption of the music, foregoing the note-taking I sometimes do during experimental-music concerts. And it was a perfect conclusion to what had been a long day of not only experimental music but art-gallery openings. But that is another story.