Re: Shake/trill

[Mike Curtis <wd6ehr@xxxxxxxxxx>]

> Just a thought, the trill is just an ornament and really an expansion of
> a true vibrato, a means of making a long note a little more attractive. 

Excellent point - that it can be thought of as a very hard vibrato!

> However, on the mouthorgan we (a lot of players) don't do a true vibrato
> which is a variation in pitch (look at a fiddle player or a guitarist,
> actually even a guitarist 'does it wrong' ) A normal vibrato, vocal or
> instrumental ,is a shift in pitch above and below the note, fiddle & voice
> do this, guitarists go from the note upwards unless they are very
> experienced. 

There are circumstances under which three forms of vibrato - raised pitch,
lowered pitch, and centered pitch - may be desired.  The one you mention
is the classic "centered pitch".  A reasonably skilled guitarist can do
all three.  For a centered pitch vibrato, the guitarist will hit a note a
half-tone (or more) flat, bend it up to the desired pitch, then apply
vibrato (usually wrist-shake) from there. 

Also, by using handshake (moving the hand back and forth parallel to the
string, causing a slight waver in string tension, ergo changing pitch) on
an unbent string, a true vibrato that (usually) centers in pitch from the
true note is achieved.  This is most often used in classical guitar, but
is also effective in blues and other styles.  However, it's much more
subtle than a hard wrist vibrato.

> Harmonica vibrato in general is a volume vibrato.  I know
> all the arguments about percieved pitch change with volume change but that
> is a side issue. Lip vibrato and some throat vibrati (!) can produce a
> similar pitch change to a guitar but in the other direction. 

In one dictionary, "vibrato" is defined as amplitude variations.  In my
music dictionary, it's defined as pitch variations.  In my experience,
pitch variation is more the accepted meaning, ergo the way I use the term.
In currently accepted technical jargon, volume variations are "tremelo" or
"tremolo"; pitch variations are "vibrato".  Complementary pitch variations
are "chorus".  Variations utilizing a comb filter are called "flanging". 
Certain manufacturers have, in the past, defined tremolo as vibrato, but
current practice is as above.  In harmonica nomenclature, it seems that 
vibrato is a catchall term for most low frequency variations, be they 
volume, phase, pitch, or timbre (e.g. hand vibrato.)

> The Lord have mercy on harmonica & guitar duos with a penchant for
> vibrato, its'orrid. 

I feel that much depends on the music, as well as the players.  A
dissonance of conflicting vibrati (is this for a fact the plural form?  My
dictionaries are silent on the matter) can produce a very pleasant
"chorus" effect.  This is one reason a large group of voices and/or
instruments doing the same note sounds so full.  If all were perfectly
identical in pitch, the sound would not be nearly so full.  It's the
slight (but definite) pitch differences that give this such a wonderfully
full sound. 

The Leslie speaker achieves this effect by rotating a pair of horns, 
utilizing Doppler shift to produce a complementary frequency shift.

The electronic "chorus" effect does this by applying a low frequency pitch
or phase shift to the original sound.  The chorus shifts this in both
directions at the same time (up and down), as opposed to a phasor or
vibrato, which shifts in a single direction at a time only. (The
modulation would look like a pair of sine waves, 180 degrees opposed,
instead of a single sinusoid.) The resulting signal is definitely
dissonant, but very full.  When a guitarist and harmonicist both use bends
and vibrati, the effect can be much the same. 

IMO, it's nice to use bends and vibrati in unison, too.  The
possible variations while playing the same "written"  notes are nothing
short of amazing. 


 -- mike