HOW TO USE JOHN GIBSON'S "addsynenv" DEMO PROGRAM
Don Byrd, 11 Sept. 2006

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
"ADSR" type envelope 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        -           -           -           -