Objective

My objective is to write a bass guitar composition and design algorithmically determined accompaniments, all based on the Fibonacci sequence.

Goals

• Finish writing a composition that I once started on my bass revolving around the Fibonacci numbers
• Design various accompaniments to this bass line also revolving around the Fibonacci sequence
• Experiment with digital audio effects, the parameters of which are manipulated based on Fibonacci sequence
• Experiment with manual manipulation of different parameters of the auto-accompaniments
• Experiment with multi-channel audio
• Use a MIDI foot pedal, or other sensors (accelerometer), to manipulate these parameters during performance of the piece

Implementation

I am hoping to achieve these goals by creating a few smaller projects to tackle each of them, and then bringing all of the techniques together in the end.

In the end I hope to have flushed out this composition I have in mind, and to have some natural sounding, algorithmically determined accompaniments in the piece. My goal is not to merely generate these accompaniments in an arbitrary way, but to ensure that the piece is still pleasing to listen to. I do not want knowledge of my development process to be a prerequisite for listening to the piece. It should stand on its own.

Features

• Entire e-commerce solution, so Kenyon can sell their products directly to customers.
• Dealer login, enabling dealers to select which products they carry
• Google Maps “Dealer Locator” which can be specific to items carried by dealer
• Administrative users can receive notification of low stock and product invoices
• Unlimited number of static pages, all editable through administrative interface
• All products & product categories handled through admin interface

Implementation

• PHP Symfony web framework
• Symfony plugins
• Javascript
  • Google Maps API
  • jQuery/Ajax
• MySQL

I’ve decided to implement this using a programming language called ChucK, which so far has been working out extremely well. ChucK is a relatively new multimedia programming language which allows you to accomplish some complicated tasks in very little time. Since I have not really done any DSP Programming before, it is extremely gratifying to be able to hear results immediately.

The way Independent Study works at RPI, is you make proposals, set goals, and complete them. Here is my proposal for my end-of-semester project: Project Proposal

Curtis Bahn is my advising professor for this project, and he has been more than helpful.

Here is an audio sample of the effect in action. There are no other alterations to the bass signal besides mixing in a bit of clean as well. The affected signal was recorded through my stack (GK-700RBII, Ampeg SVT410HLF) using my Zoom H4n. The distortion increases as I play my bass louder, as you can hear towards the end of the clip.

ChucK ended up working very well. I think the effect sounds pretty good. As you can see below, there are infinitely many options available for the coefficients of the wavetable function (Gen17 object in ChucK). I can spend hours tweaking them, but the ones I settled on are uncommented below.

Click to show code.

/**
*  Overdrive/Distortion effect (meant for bass guitar)
*
*  Copyright (c) 2009 Colin Sullivan
*
*  Permission is hereby granted, free of charge, to any person obtaining a copy
*  of this software and associated documentation files (the "Software"), to deal
*  in the Software without restriction, including without limitation the rights
*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
*  copies of the Software, and to permit persons to whom the Software is
*  furnished to do so, subject to the following conditions:
*
*  The above copyright notice and this permission notice shall be included in
*  all copies or substantial portions of the Software.
*
*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
*  THE SOFTWARE.
**/

// patch
//envelope follower
adc => Gain g => OnePole p => blackhole;
//clean lows
adc => LPF lowpass => Gain lowClean => Gain mix;
//overdrive on lows
lowpass => Gen17 lowOD => mix;
//clean highs
adc => BPF highpass => Gain highClean => mix;
//overdrive on highs
adc => highpass => Gen17 highOD => mix;
//mix them together
mix => dac;

//master Levels
mix.gain(0);
1  => float masterVolumeLimit;

//low levels
lowClean.gain(1); //1
lowOD.gain(0); //0.3

//high levels
highClean.gain(1); //0.3
highOD.gain(0); //1

//frequency of pass filters
lowpass.freq(1000);
highpass.set(1000, 1000/(1200-800) );

//square input
adc => g;
//multiply
3 => g.op;
// set pole position
0.9999 => p.pole;

// load up the coeffs; amplitudes for successive partials
lowOD.coefs( [ 1., 0.5, 0, 0.5, 1. ] ); //Nice fat fuzz
//lowOD.coefs( [1., 0.5, 0, -0.5, -1.] );  //thrashy, but buzz
//lowOD.coefs( [.99, .88, 0, .88, -.99] );	//loud and farty fuzz
// load up the coeffs; amplitudes for successive partials
//highOD.coefs( [ 1., 0.5, 0, 0.5, 1. ] );
//highOD.coefs( [1., 0.5, 0, -0.5, -1.] );
//highOD.coefs( [.99, .88, 0, .88, -.99] );
//highOD.coefs( [0.5, 0, -0.5] );
highOD.coefs( [.256, -.576, .432, -.120, .9] ); //not grungy enough

//master volume
0 => float masterVolume;
0 => float i;

// will hold last value of filter
0 => float pLast;
// full overdrive flag
0 => int fullOD;

// Allows output to chuck~ object outlet in Max/MSP
MaxMessage m;

while (true) {
  while(masterVolume < masterVolumeLimit) {
    mix.gain(masterVolume);
    0.001 +=> masterVolume;
    1::ms => now;
  }

  // Get last value of filter
  p.last()*50 => pLast;

  // Debug to max
  //pLast => m.floatout;

  // Set high overdrive gain based on dynamics of playing
  if(pLast < 1 && fullOD == 0)
  {
    highOD.gain(pLast);
    lowOD.gain(0.3*pLast);
  }
  else if(pLast >= 1)
  {
    highOD.gain(1);
    lowOD.gain(0.3);
    1 => fullOD;
  }
  else if(pLast < 0.5 && fullOD == 1)
  {
    // turn fullOD flag off if done lowering
    if(highOD.gain() - pLast < 0.001)
    {
      0 => fullOD;
    }
    else
    {
      // Lower gain
      highOD.gain(highOD.gain() - 0.001);
    }
  }
  0.01 +=> i;
  1::ms => now;
}

We use jQuery for all manipulations and Ajax calls, and PHP/MySQL for the back-end.

For more information about the project, http://www.rpinventory.com/.

Written in PHP/MySQL/Ajax, it is another dynamic web application.

I’ve been working on PyroInventory for the past two months, and am pretty proud of it.  A demo will be available soon.