Vibrato

[Richard M Warren <rmwarren@xxxxxxxxxxx>]

Since questions have been raised concerning vibrato, I would like to call
attention to a remarkable observation reported by Seashore (University of
Iowa Studies:  Studies in the Psychology of Music, Vol. III, 1936, p. 105)
that has intrigued me for some time, and wonder if anyone knows of an
experimental verification of the phenomenon as described in the following
quote:

>... in the normal vibrato which involves pitch, loudness, and timbre,
>even the best ear can not isolate or identify these elements, to any
>satisfactory degree, by direct hearing.  We make the situation even more
>critical and striking when we produce experimental tones in which we
>present either a pitch or an intensity pulsation alone and ask the
>musician to say which it is.  Even under these circumstances, a good
>musician is quite unable to say which is which, even when the extent
>approaches the normal extent for pitch or intensity.  For example, if we
>have in one case an intensity wave of 5 decibels and in another a pitch
>wave of a half-tone, he is almost as likely to call the intensity pitch,
>or the pitch intensity, as to call them correctly.... Many musicians will
>immediately take exception to this paragraph and say, "There is no danger
>in my confusing pitch and intensity in the vibrato."  That is just
>another proof of the vitality of the illusion, because any one who has
>such a conviction quickly can be disillusioned by submitting himself to
>the test described.