HOW TO USE JOHN GIBSON'S "addsynenv" DEMO PROGRAM
Don Byrd, rev. 1 Nov. 2007

addsynenv is a Max/MSP runtime program that performs additive synthesis of up to six
partials. Each partial has an arbitrary partial number and starting phase, and an
envelope that's _piecewise linear_, like an "ADSR", but with any number of
breakpoints. It plays a single note in the waveform specified by the partials and
envelopes, and simultaneously displays either a _spectrogram_ or a _sonogram_ (see
below). Unfortunately, it can't display the note's waveform or its overall envelope.

- To start the audio driver (so you can hear something!), click the speaker icon.
- To play a note with the current settings, click the "Play a note" button. 
- Duration is in milliseconds; frequency is in Hertz.
- The button above "sono $1" switches between spectrogram and sonogram display.
- Choose presets by clicking on squares in the preset grid at the lower right.
- To create a new preset (with settings copied from the current one), shift-click
  on its little square.
- For the envelopes, drag breakpoints around in the obvious way. Click to create a
  new breakpoint; shift-click an existing breakpoint to delete it.
- To change a number, either (1) press the mouse button over it and push up or down
  to adjust its current value, or (2) click on the little triangle to its left,
  type a new value, and hit the enter key.
- There seems to be no way to save either new presets or changes to existing ones.

The spectrogram (displaying the spectrum in real time) or sonogram (showing in
color a series of spectral images) appears in the panel along the bottom of the window.
With a spectrogram, the x-axis shows frequency, and its labeling, indicating it goes
from 0 to 10 kHz, is correct. The y-axis shows amplitude at a given frequency. But
with a sonogram, the label is totally wrong!: Time is displayed from left to right
and frequency from bottom to top; amplitude at a given frequency is indicated via
color. (NB the terminology distinction between "spectrogram" and "sonogram" isn't
standard; oh well.)

The presets might be described, in a word or two each, as follows. (The words are
merely suggestive and should not be taken too seriously.)

1           2           3           4           5           6
Nasal       Organ       Detuned     Brass       Clarinet    Scary

7           8           9           10          11          12
Whole-tone  Bell        -           -           -           -