Thursday, October 23, 2014

Organ Donor Opus 1 at YouTopia 2014

YouTopia is the official San Diego Burning Man Regional event. Held annually in October at the La Jolla Indian Campground, it draws several thousand people each year to a festival of music and art. A Center Camp, dozens of theme camps, individual camping, and RV camping are placed along the narrow lacework of unpaved roads within the campground. 
The part of San Diego where YouTopia is held is located in the foothills of Palomar Mountain. There are trees and seasonal streams, poison oak and bees. Nighttime skies are very dark despite being well within striking distance of San Diego. Overnight temperatures are lower than near the coast with daytime temperatues largely equivalent. Mist, fog, and rain commonly occurs during the festival from hill effect, but is usually light. 
Sol Diego artists collective ( applied for and was placed as a theme camp. YouTopia city planning divided the event into areas based on, among other factors, how loud the sound camps were intended to be. We were located in Darwin, near the entrance. This was intended to be one of the quieter areas, and it worked out that way for us. 
Sol Diego Theme Camp provided the Sol Pyramid, Organ Donor,  and the colaser cutter workshop by Paul with demonstration of work products. Brandie Maddalena presented her program of You Are The Art at YouTalks. Brandie was also a lead for the YouTopia Temple project, which was constructed at colab and built for YouTopia.
Early entry was on Wednesday, 15 October 2014. We arrived with Organ Donor packed in the travel trailer and tow vehicle in the evening. Part of Sol Pyramid has already arrived. The remainder arrived Thursday, 16 October. The pyramid was completed late Friday afternoon, 17 October. Physcial construction of Organ Donor took from late Friday afternoon until 1:00am Saturday, 18 October. Configuration of the MTPs, the controllers that translate MIDI commands into signals for the solenoids, took about 90 minutes on Saturday morning, 18 October. This step is necessary in order to map the randomly assigned pipes to the holes in the windchest. 
This shortened schedule was not ideal, as it gave only a day and a night of demonstration. The idea of arriving early, on Wednesday, was to set up and get several days worth of experminatation, modification, and feedback. The intended schedule was not met due to the size of the pyramid and the dependence on a mechanical lift to construct it on site. 
Despite the limited time, several hundred people came to the pyramid and played with, listened to, and talked about the Organ Donor. The feedback was valuable, and the project received favorable reviews. 
Organ Donor opus 1 as deployed at YouTopia 2014 had an eight-foot and a four-foot rank. The upper keyboard, in the pair of keyboards, played the four-foot rank. The lower keyboard played the eight-foot rank. Organ Donor Paul created a console and a controller that allowed registration to be selected by the operator. By pressing LED-backlight buttons, the operator could select single notes, select notes plus an octave above, select notes plus an octave below, select notes plus an octave above and an octave below, and crosslinking to the other rank. The console case was cut out of quarter-inch plywood on the colab laser cutter.
The pipes were not tunable as deployed. They were cut to calculated length and their pitches measured. Results were recorded in a spreadsheet. Results showed that the pipes were all consistently flat. When played together, some intonation issues were heard, but the overall tuning effect was acceptable.  
A small number of pipes did not play (were silent) at the designed wind pressure. The pipes were correctly connected and the solenoids observed to be working. All of these pipes could be manually played, but were quiet or required substantially more pressure to sound. It was therefore not suprising that the regulated pressure from the windchest did not sound them. These pipes will probably have to be re-cut.  
The smallest pipes had the most fallout, with the 4-foot rank suffering the most attrition in the highest notes. All pipes could be manually played, but at 2 inches of wind pressure, several were unexpectedly silent.
The largest pipes were quieter than expected but all successfully sounded.
During windchest construction, ciphers (valves that don’t completely close) were observed and tracked in a spreadsheet. Efforts were made to improve the seal between the pallet pad and the hole of the windchest. This greatly reduced, but did not completely eliminate, the number and severity of the ciphers. 
During deployment, when ciphers were identified, larger pipes were assigned to the ciphers. Since the volume of air required to sound larger pipes is larger than the volume of air required to sound smaller pipes, putting larger pipes on the ciphers succeeds in reducing or eliminating the irritating sound that a constantly playing pipe can cause. Two holes were not successfully reassigned, so the pipes were dropped from the ranks. 
During MIDI file playback, where the MIDI commands come from a file rather than an operator playing the MIDI keyboards, problems were observed. We saw that there were notes that stayed on. After printing out messages to the console and comparing the messages sent from the file to the messages interpreted by the console controller, it was observed that, occaisionally, “note off” MIDI messages were not appearing. The root cause was not identified until after returning to San Diego. The missing messages were from what appeared to be a misconfiguration between the MIDI conversion cable and the MIDI driver, and not code in either the computer playing the files, or the Arduino at the heart of the controller that arbitrates which MIDI messages are passed through to the MTPs. 
Fuses blew several times when operators played large numbers of notes. The fuse was set to a conservative level in order to protect the equipment. While easy to change out, it did interrupt a recital of Phantom of the Opera and a wide-ranging version of Heart and Soul among other works. The number of simultaneous notes allowed to be played is controlled by the Arduino arbitration controller in the console. The fuse selection for the weekend was below this software limit. It was not expected that the current consumption would reach this level, and observations of the meter supported this assumption. It is quite possible that startup currents were the reason for fuse wear. A review of current consumption controls, power supply design, and protection circuitry is ongoing.
Operators greatly enjoyed playing the Organ Donor opus 1. The instrument was busy the entire time it was available, all day Saturday and late into Saturday night and early Sunday morning. Operators were enthusiastic and spread the word. The demogrpahics of the event resulted in a large number of trained keyboard players, music theoreticians, other makers, and interested programmers. Outreach from Sol Diego Organ Donor to the local Burning Man community was successful. 
It was decided that the next deployment would be Borrego Days, held the following weekend in Borrego Springs, CA.

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