Since force sensing resistors from Interlink Electronics are expensive ($5-6/each) and also because I couldn’t see how the fragile FSRs would fit into the holes we planned to use, I wanted to find a better solution.

I discovered it was possible to create FSRs out of wire and plastic wrap. Others have used conductive foam and wire mesh. Reading about linear position sensors also gave some insights.

I took 22 gauge wire from the physcomp lab, stripped it, and bent it back and forth to mimic the “fingers” on the FSRs I purchased from Interlink. After making two wire finger pieces, I wrapped one in seven layers of plastic wrap. I place the second set of wire fingers on the outside of the package and wrapped it into the existing package. My first few tests seemed very promising. When no pressure was applied to the package, the resistance was infinite. When I squashed the package, the resistance dropped down to about 10K.

The next trick was to try to duplicate this behavior on the end of a PVC pipe. We first tried applying the plastic wrap/wire packages around the end of the PVC pipe. The results were less encouraging than my initial experiments.

The homemade sensors were unreliable: either the sensor package was too tightly squashed between the PVC and the surrounding hole (and gave no resistance) or it was too loose and no amoung of bending the pole caused a reading.

We went to Home Depot in search of bamboo and springs, but came back with 1/2″ (ID) PVC and cast iron flanges.

The bamboo remains a cost-effective option ($1.79 for a package of 4-5 x 5′ stalks).

We attached 3/4″ x 1/2″ reducing adapters onto one end of ~5′ x 1/2″ (i.d.) PVC pipes and screwed them into a 3/4″ flanges mounted on a sheet of plywood. We painted the PVC poles hunter green to loosely reference a field of tall grass.

We created the prototype with two poles on it to see how the poles would flex as people move through them.

It was a great day to work outside and we were pleased with the progress we made.

Construction Lessons
- When cutting plywood, cut through the side you wish to display so the ragged edges are hidden
- Plan the flange installation better so the holes will line up on the top and bottom playwood pieces
- We will need to custom cut a 4′x8′ plywood sheet to get the 6′x3′ installation we want

Sound
We made further progress as we began to discuss the sound of the field. Both of us were drawn to the opening bars of Stravinsky’s Rite of Spring. The was some initial confusion about whether we were listening to the “Rite of Spring” or the “Firebird Suite”, but I resolved that as of this writing. The solo oboe (or perhaps clarinet?) provides a mysterious sonic backdrop for exploring a new space. We plan to edit a small sample from the first track and control its playback using the sensors we are planning to attach to the PVC poles. As users enter the installation, they will have the opportunity to push their way through our sound field. Each subsequent PVC pole they push will play the next piece of the sample we’ve chosen. If they walk push through the field at the right speed (according to the mood of the selected piece), they will hear the melody as they move.

Why?
- We’ve both done field recordings
- Alice interested in the creative potential in the raw content she’s been capturing
- I want to see what can be done compositionally with speech as a “generator,” for melody; many people seem to have musical voices

Process
- Tried two approaches initially: compositional & computational

- Attempted to write melodies from in-class recordings by listening and transcribing. This is time-consuming — and made further difficult by the distraction of the meaning of the spoken words. Perhaps it is easier when you don’t know the people who are speaking or don’t care about the content of the discussion… but in our case we were too close.

- Attempted to create a pitch-following patch in MAX/MSP. The idea behind pitch-following was to separate the frequency spectrum into separate slots – ideally a half-step apart and then track which slot had the greatest energy level.

Pitch-Following Resources
- Fiddle – MAX/MSP patch for continuous pitch tracking
- Paper: Strategies for Continuous Pitch and Amplitude Tracking in Realtime Interactive Improvisation Software
- My earlier experiments

Listening Selections
Larry Austin – 3 tracks audio portrait of Joan La Barabara (obtained at Avery Fischer Media Center in Bobst Library)
Joan La Barbara – 73 poems
Thomas Buckner – “His Tone of Voice at 37″
Paul DeMarinis – Music as a second Language:“An Appeal”
Laurie Anderson – “NY Social Life” (requires NYU ID/password)
Bobby McFerrin http://www.youtube.com/watch?v=LtXrKo8Btfc

Bertoia Sound Sculptures
- An online catelog of sorts. Minimalist aesthetics.

Sonic Architecture
- Works from architects/designers Bill and Marv Buchen. Many are located around NYC.

We scrapped the pickup idea after measuring the resistance of the coil to be 0 Ohms. I was concerned it might short something out. Shlomit also thought we would have more creative possibilities if we used sensors rather than capturing the sound of the springs directly.

Returning to a previous sensing idea, we experimented with a flex sensors.

Flex sensors are not ideal for our application; they only sense motion in one direction and require a fair amount of deflection in order to produce a useful reading. (note for the future… measurement ranges would be useful for documentation purposes)

We also considered mounting the springs on top of a pair of joystick potentiometers to sense X-Y movement. The miniature potentiometer we tried to use for our prototype was too stiff to yield useful results. We wrapped a copper wire around the dial of the potentiometer, hoping that motion of the springs on our installation mockup would move the potetiometer and generate a varying resistance. No luck.

I ran into trouble finding the frequency bin with the maximum energy. Jonathan Marcus helped me with a solution to that problem using the zl object.

The patch makes some sounds now, but still not what I hoped for. I wanted a patch that would highlight the musicality of recorded speech. I expect it would work better on some voices than others, but so far it just sounds “random.”

• When the .wav file is silent, the patch plays the last frequency in the frequency transform list (to fix, I will need to detect that case and turn off the cycle~ object)
• I tried testing the patch with the cycle~ object as an input, thinking that a pure tone would be a good way to test the patch’s ability to recognize frequencies. As I changed the frequencies of the cycle~ object going into the patch, there were some spots where the pitch detection “blew up” and returned to the highest frequency in my list.
• More experimentation needs to be done with voice recordings to see how they respond. I will post some results soon.

Using the patch
- Enable the DAC
- Click the “open” message to load a file into the sfplay~ object
- Click the “1″ attached the sfplay~ object to start playback
- The following controls modify the output: transform strength, wave volume, and transform volume
- “Transform Strength” controls the scaling of the values coming out of the fffb~. Increasing the transform strength with cause larger numbers to be packed into the frequency bin energy list. This primarily affects the height of the peaks on the multislider display.
- “Wave Volume” and “Transform Volume” adjust the relative sound levels of the original .wav file and the transformed signal. Set transform volume higher than wave volume to emphasize the transformed sound.

To try out this patch, simply copy the following lines and paste them into MAX/MSP

#P window setfont “Sans Serif” 9.;
#P window linecount 9;
#P comment 399 18 143 9109513 fffb~ is used here to break the audio from the .wav file into separate frequency bands. The band with the most energy will choose the frequency to be played. In this way \, I hope to create a system which highlights the melodic aspects of human speech.;
#P window linecount 1;
#P newex 70 478 33 9109513 *~ 0.5;
#P flonum 110 430 35 9 0 0 0 139 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 234 551 35 9 0 0 0 139 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 246 105 35 9 0 0 0 139 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 459 301 35 9 0 0 0 139 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 529 300 35 9 0 0 0 139 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 580 301 35 9 0 0 0 139 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 248 370 395 9109513 60. 120. 180. 240. 440. 510 530 600 660 700 725 800 880 900 910 940 1000 1060 1120 1180;
#P newex 185 489 35 9109513 zl reg;
#P newex 185 456 72 9109513 t b i;
#P newex 184 520 35 9109513 zl nth;
#P newex 185 428 36 9109513 zl sub;
#P newex 211 403 65 9109513 maximum 0.;
#P newex 185 379 36 9109513 t l l;
#P newex 185 613 33 9109513 *~ 0.8;
#P newex 184 579 36 9109513 cycle~;
#P flonum 184 555 35 9 0 0 0 139 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 106 77 14 9109513 0;
#P message 87 77 14 9109513 1;
#P message 47 77 28 9109513 open;
#P newex 524 257 33 9109513 * 128.;
#P newex 524 230 29 9109513 avg~;
#P newex 484 257 33 9109513 * 128.;
#P newex 484 230 29 9109513 avg~;
#P newex 441 257 33 9109513 * 128.;
#P newex 444 230 29 9109513 avg~;
#P newex 404 257 33 9109513 * 128.;
#P newex 404 230 29 9109513 avg~;
#P newex 364 257 33 9109513 * 128.;
#P newex 364 230 29 9109513 avg~;
#P newex 324 257 33 9109513 * 128.;
#P newex 324 230 29 9109513 avg~;
#P newex 284 257 33 9109513 * 128.;
#P newex 284 230 29 9109513 avg~;
#P newex 244 257 33 9109513 * 128.;
#P newex 244 230 29 9109513 avg~;
#P toggle 176 77 15 0;
#P newex 176 105 50 9109513 metro 100;
#P toggle 13 77 15 0;
#P newex 201 258 33 9109513 * 128.;
#P newex 201 231 29 9109513 avg~;
#P newex 161 258 33 9109513 * 128.;
#P newex 161 231 29 9109513 avg~;
#P newex 121 258 33 9109513 * 128.;
#P newex 121 231 29 9109513 avg~;
#P newex 185 326 160 9109513 pack 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.;
#P newex 81 258 33 9109513 * 128.;
#P newex 81 231 29 9109513 avg~;
#P user multiSlider 300 440 200 96 0. 75. 12 2937 15 0 0 2 0 0 0;
#M frgb 249 203 82;
#M brgb 255 255 255;
#M rgb2 127 127 127;
#M rgb3 0 0 0;
#M rgb4 37 52 91;
#M rgb5 74 105 182;
#M rgb6 112 158 18;
#M rgb7 149 211 110;
#M rgb8 187 9 201;
#M rgb9 224 62 37;
#M rgb10 7 114 128;
#P newex 145 667 28 9109513 dac~;
#N sfplay~ 2 120960 0 ;
#P newobj 62 105 48 9109513 sfplay~ 2;
#P newex 114 159 157 9109513 fffb~ 12 60 0.5 0.1;
#P window linecount 2;
#P comment 233 522 49 9109513 Transform Volume;
#P window linecount 1;
#P comment 284 101 100 9109513 transform strength;
#P window linecount 2;
#P comment 106 400 67 9109513 Wave Volume;
#P window linecount 0;
#P comment 1011 12 100 9109513;
#P window linecount 1;
#P comment 12 53 29 9109513 DAC;
#P comment 45 52 100 9109513 WAV File Control;
#P comment 299 414 100 9109513 Frequency Response;
#P comment 248 352 141 9109513 List of frequencies to play;
#P window linecount 5;
#P comment 220 18 170 9109513 Michael Chladil 3/29/2007 MAX/MSP programming help from Jeremy Rozenstein Jonathan Lee Marcus;
#P connect 43 0 10 0;
#P connect 42 0 10 0;
#P connect 41 0 10 0;
#P connect 10 1 60 0;
#P connect 10 0 60 0;
#P connect 23 0 13 0;
#P connect 9 0 13 0;
#P connect 13 0 14 0;
#P connect 59 0 60 1;
#P connect 57 0 14 1;
#P connect 10 1 9 0;
#P connect 10 0 9 0;
#P connect 23 0 16 0;
#P connect 9 1 16 0;
#P connect 16 0 17 0;
#P connect 57 0 17 1;
#P connect 46 0 11 0;
#P connect 22 0 11 0;
#P connect 60 0 11 0;
#P connect 23 0 18 0;
#P connect 9 2 18 0;
#P connect 18 0 19 0;
#P connect 46 0 11 1;
#P connect 24 0 23 0;
#P connect 57 0 19 1;
#P connect 52 0 50 0;
#P connect 50 0 44 0;
#P connect 44 0 45 0;
#P connect 14 0 15 0;
#P connect 15 0 47 0;
#P connect 47 0 49 0;
#P connect 49 0 51 0;
#P connect 51 0 52 0;
#P connect 45 0 46 0;
#P connect 17 0 15 1;
#P connect 23 0 20 0;
#P connect 9 3 20 0;
#P connect 20 0 21 0;
#P connect 58 0 46 1;
#P connect 51 1 50 1;
#P connect 53 0 52 1;
#P connect 19 0 15 2;
#P connect 47 1 48 0;
#P connect 48 0 49 1;
#P connect 57 0 21 1;
#P connect 21 0 15 3;
#P connect 26 0 15 4;
#P connect 23 0 25 0;
#P connect 9 4 25 0;
#P connect 25 0 26 0;
#P connect 28 0 15 5;
#P connect 30 0 15 6;
#P connect 57 0 26 1;
#P connect 32 0 15 7;
#P connect 23 0 27 0;
#P connect 9 5 27 0;
#P connect 27 0 28 0;
#P connect 34 0 15 8;
#P connect 15 0 12 0;
#P connect 36 0 15 9;
#P connect 57 0 28 1;
#P connect 38 0 15 10;
#P connect 23 0 29 0;
#P connect 9 6 29 0;
#P connect 29 0 30 0;
#P connect 40 0 15 11;
#P connect 57 0 30 1;
#P connect 23 0 31 0;
#P connect 9 7 31 0;
#P connect 31 0 32 0;
#P connect 57 0 32 1;
#P connect 23 0 33 0;
#P connect 9 8 33 0;
#P connect 33 0 34 0;
#P connect 57 0 34 1;
#P connect 35 0 36 0;
#P connect 23 0 35 0;
#P connect 9 9 35 0;
#P connect 36 0 56 0;
#P connect 57 0 36 1;
#P connect 23 0 37 0;
#P connect 9 10 37 0;
#P connect 37 0 38 0;
#P connect 57 0 38 1;
#P connect 23 0 39 0;
#P connect 9 11 39 0;
#P connect 39 0 40 0;
#P connect 38 0 55 0;
#P connect 57 0 40 1;
#P connect 40 0 54 0;
#P window clipboard copycount 62;

]]> http://ropeandpulley.com/blog/2007/03/30/musical-speech/feed/ 0 http://ropeandpulley.com/blog/2007/03/28/final-project-progress/?utm_source=rss&utm_medium=rss&utm_campaign=final-project-progress http://ropeandpulley.com/blog/2007/03/28/final-project-progress/#comments Thu, 29 Mar 2007 00:55:12 +0000 Michael http://ropeandpulley.com/blog/?p=96 Shlomit and I made some progress on our audio art final. We decided to build a sonic field of springs.

Strategies for sensing movement:

• Flex sensor
• Magnetic pickup (like electric guitar)
• 2-axis potentiometer (joystick)

After brainstorming more about producing sound and sensing movement, we built a tiny prototype, using the technique I discovered while building a prototype for Designing for Constraints.

]]> http://ropeandpulley.com/blog/2007/03/28/final-project-progress/feed/ 0 http://ropeandpulley.com/blog/2007/03/23/music-creation-for-non-musicians/?utm_source=rss&utm_medium=rss&utm_campaign=music-creation-for-non-musicians http://ropeandpulley.com/blog/2007/03/23/music-creation-for-non-musicians/#comments Sat, 24 Mar 2007 02:43:41 +0000 Michael http://ropeandpulley.com/blog/?p=92 Aaron Siegel and Chris Peck and were guest lecturers in Audio Art this afternoon. Both compose works for untrained performers. This is one of the reasons I came to study at ITP. I want to design systems to enable untrained performers to collaborate musically.

Aaron’s piece “Work in Manufacturing” was a percussive piece with fixed rules, but varying outcomes regulated by each performer’s breathing. The rules of the piece made me feel disoriented at times because I had to keep a number of things in mind: how times I had inhaled or exhaled since beginning my current “station,” how many “stations” I had completed, and the number I had chosen as my “jump” number for selecting subsequent stations.

The overall sound of the piece was intriguing, but I prefer tonal music.

Chris’ piece “Worried Long” was a “choral” piece. I found it easier to appreciate the quality of the sound in this piece because it was richer and sustained. It sounded majestic as we sang it. I was very surprised at how harmonic it sounded — even though none of us knew the intervals we were supposed to sing. Further, only about half the class was musically trained. I don’t know how many of us could say that we know how to sing, but I really enjoyed the sound we created and would definitely consider it music. The dynamics were incredible and it was invigorating to belt out the slowed down lyrics with the rest of the class as we reached the climax of the piece.

I’ve been thinking about the discussion Amit and I had about believability. Both of the pieces seemed to have that quality. I knew nothing of the two composers beyond their remarks prior to performing the pieces, but it seemed that each piece matched the personality of its composer. Additionally, it was believable that we were creating the music together. Neither piece asked us to make an “impossible” committments in performing them. Collectively, we had all of the skills necessary to render the works. There was no need to think about which performers would be capable of properly interpreting their parts.

]]> http://ropeandpulley.com/blog/2007/03/23/music-creation-for-non-musicians/feed/ 0