Programming Sound - Project #2
Additive Bell Instrument
For this project, create a MAX/MSP patch which is based on the synthesis flowchart of Jean-Claude Risset's Bell Synthesis Algorithm found in Dodge's book on page 94 (and below). This patch should produce bell tones when triggered using the data found in the description for pitch and envelopes of each bell.
If possible, try to use a midi kcontroller (keyboard) at the top of the patch. Map the midi notes to pitch (use the mtof object to convert midi note numbers to pitch) and velocity to amplitude (remember, MIDI velocities are 0-127, and the kcontroller uses the vertical location you click to control velocity). This way, you can play your bell instrument from the keyboard.
A few hints:
Keep in mind that the envelopes are exponential decays from 1 to 2(-10). Try starting with a duration of 20 seconds. Use the curve~ object with a parameter value of between negative .5 and negative .7 (curve~ is just like line~, but produces approximations of exponential envelopes) to produce a 1-0 exponential output: See curve~'s help patch for an example.
Make a patcher or abstraction for each unit of the additive synthesis structure (an abstraction is best). This means that you would create a seperate patch saved in your working directory with inlets (or arguments) for pitch, amplitude, and duration, as well as a trigger inlet. The audio signal would come out the outlet. Then, constructing the larger patch which uses all of these together is a simple process.
Experiment around with various values and envelope shapes, as well as various amounts of "detuning" of the partials.
All projects should be emailed to me (complete MAX patch and any sub-patches stuffed into a .sit file - if you don't know how to do this, you should - so see me...) at: sdecker@artic.edu.
In order to pass this class, you must have successfully completed ALL projects! (Projects are only successfully completed when you have mailed them to me, and I have responded that they are complete.)
For your reference, here is the diagram from Risset's text. There is also an important discussion of this instrument within the text - please look over this and make sure that you understand everything before beginning the project!
