Renaming false beats...was False beats ....was M&A A

[RicB]

Hi Ed

For my part, whenever I take up this discussion I am refereing to the 
classic false beat.  That false beat which sounds just like two strings 
beating when slightly out of tune..... that false beat that slows down, 
stops and then speeds up again when applying (increasing)  pressure 
sideways on the pin of the offending string. That kind of takes care of 
your first bit. I think Paul and I are on the same page here in any case.

Your question relative to pitch change or a change of amplitude..... It 
is my understanding that the classic false beat is caused by the 
termination as a whole moving in phase with the strings vibration in one 
direction at a given frequency whilst not moving in phase at that same 
frequency in another direction. Thereby you get a beat... which by 
definition includes a change of amplitude.

I dont think the classic false beat has anything to do with the capo... 
or agraffes... they are too massive perhaps ?

There are other kinds of falsness, related and not. I suppose its 
possible for a termination to vibrate in phase in two directions and not 
in a third... with the two in phase vibrations going at different 
amplitudes causing a conglomerate falsness that would easily be heard as 
a kind of wavering... warble as you mention. 

Just a few thoughts in response to your post.

Cheers
RicB

    For thinking purposes, how about "Apparent periodic pitch fluctuation?"

    Questions:

    Are we talking about one phenomenon of several phenomena with
    similar sounds?  If so, can we categorize the phenomena to avoid
    endless wheel spinning?  Can we provide a diagnostic for this?

    Is the phenomenon really a pitch change or a change of amplitude
    that we hear as a pitch change?

    Is the phenomenon a change of timbre that we hear as pitch change?

    Is the phenomenon mostly limited to the capo region, or does our
    perception assume the "beating quality" in this area?  Is this
    because of the mechanics of the capo (vs agraffe)?  Or is it because
    of the frequencies in the capo area; and if so, is this a matter of
    physics or psychophysics?

    Bass strings often exhibit warbles, beats and whines at high
    frequencies.  These problems originate in the string itself, not in
    the rest of the piano.  Does this bear any relation to sound
    anomalies in plainwire strings?

    Ed Sutton