beat frequencies and harmonic content

[Richard Moody]

I have wondered about the beats affecting each other in a major triad.  On
the piano the triads don't seem to have a descernible beat.    On paper it
looks like three beats are interacting.  The fifth beats too slow I think
to matter.   Taking the C major,  the C - E = 10.4 the E -G minor third  =
17.8.  If beat frequencies act like regular frequencies the difference
between them should be another beat, in this case 7.4 bps.   
	On the piano, I have never heard much in the triads (root positon), and
don't listen much there.  However on the synthesizer it is a different
story.  There is a beat in the C major (middle C) triad, and it sounds a
tisch faster than the C -E third below.   Looking again at the beat table
I see the rate for that third is 7.06 and the D# third 7.47 so once once
again paper pans out.  
	The synth aids in hearing these beats in three ways. First and formost
the tone sustains. With piano tone diminishing in volume, so does the
volume of beats, which interferes with hearing the beats since they are
really only a periodic increasing and decreasing volume.   The strength of
volume of the partials on the synth at least with saw tooth, seem to be a
bit more than on the piano.  This may be because the level of sustain
remains constant.  Actually the manual  says the "when the fundamental
content is 1, the content of the nth harmonic is 1/n"   This means the
third hamonic is 1/3 the level of the fundamental. I wonder how that works
out on the piano.   

Richard Moody 

----------
> From: Jon Page <jpage@capecod.net>
> To: pianotech@ptg.org
> Subject: Re: Tuning
> Date: Saturday, October 17, 1998 11:19 AM
> 
> No one has mentioned the test of a major triad
> cancelling out the rolling beats of the fifth.
> 
> Jon Page
> Harwich Port, Cape Cod, Mass. (jpage@capecod.net)
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>