On Mon, Mar 29, 2021 at 09:41:16AM +0200, Tom Peters wrote:
> Bill,
> thank you for making the diagram. What do you use to convert a .ogg file 
> to a graph?
I guess that depends on your OS.  I used a utility on the Haiku OS I run,
and can verify Bill's statements.  I can also verify that there is a considerable
subjective variation in the amplitudes of the sequence when listening!
I'm not sure if it's resonance in my audio or what, but the first of your
sounds seems much louder than the others.  To check that this wasn't
a "first one" effect, I added in the [64/81] sound at the start (which is much
softer to me), and the "440 [3/2]" tone is still the (subjective) loudest.

OK, I just used headphones from my laptop audio, and the effect is the same.
Guess it's my ears!  If I just use the laptop's own (tinny!) speakers, the effect
is very pronounced.  Can hardly hear the later notes.

> All my notes are programmed to play for 1 second, but from the graph I 
> see that they are not neatly separated but blend one into the other, 
> showing beat frequencies. Only the last note tapers off as I intended. 
> So Dave Seidel may be right that somehow the envelope stretches each 
> note to 1.2 seconds.

Yes, as I understand it, that's how madsr works.  The release time is *added on*
to the p3 of the note. The madsr page is not very clear, but it says it uses 'linsegr'
and that page says:
"When [it] senses an event termination or MIDI noteoff, it immediately extends
the performance time of the current instrument by irel seconds, and sets out to
reach the value iz by the end of that period (no matter which segment the unit is in"

> Any idea what might be going on, or how the madsr should be used?

I just changed all notes in the score except the first to:
      i 1 ^+1.5 . 440 [4/3]
etc. 
 (I.e. replaced "+" with "^+1.5", so the notes are 1.5 secs apart, but still
only 1 second long.)  No beat frequencies now, but the effect is still there.

	-- Pete --

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