Graphing
Vocal Vibrato
Most Western vocalists have a vibrato that
far exceeds the bounds of one semitone, so the display on the lower
graph becomes quite useless. Any particular note changes its semitone
identity rapidly, during a time we wish to think of it as one
particular semitone.
The Lower Graph is useless.
The solution is to expand the pitch range covered by
the lower graph; this results in diminished magnification, but keeps
the vibrato within the range of the graph. To effect this, select a View | Lower Graph Scaling that is greater
than the default of 10 cents per division. If, for instance, the
vibrato oscillates two semitones top to bottom, then it would just fit in the 20 cents per
division scaling, if it were exactly
in tune. Since it won't be, 30 cents per division is the
appropriate choice.
Here is a short trace to explain the concept. As
before, the orange boxes show the area being mapped by the lower graph.
Note the labels - the scaling has changed, and each dashed line
represents a tuning differential of 30 cents. Since the lower graph now
extends into the surrounding semitones, the centers of those semitones
are also colored in on the graph. [to make that clear, the semitone
lines C, B, and A# are labeled for the note B, the third box in the trace].
Parsing the beginning and ending of individual notes
is quite imperfect in this mode. You will almost always encounter
incorrect assignment of the semitone at the beginning of a note;
it is unavoidable. Nevertheless, you will have the precise pitch
feedback for the main part of the note - this is certainly enough
information to help you refine your intonation. Furthermore, the upper
graph will be correct, it doesn't depend on separating the tune into
this or that semitone. So it can always serve to show you how your
notes begin. The end of a note is usually correct in the lower graph,
just that it may continue in that color while the next note begins,
until enough time has elapsed for the new note to become clear to
TuningMeister.
In the above example, it takes a while for TM to
lock in on the E, which is the first note. Then
the pitch of E, which starts out well-centered, rises to about 30 cents
or more sharp, as can be read from the black averaging trace in the
lower graph. (Once
TM settles on E as a solid note, the averaging graph can't begin until
one cycle of the vibrato has occurred.) The
D lies a bit sharp from the beginning, and gets sharper and sharper at
the end until finally it breaks into the region of Eb. Then it drifts
down preparatory to the consonant that begins the B - the upper graph
shows some breaks where the consonant is pronounced, then the lower
graph locks onto the B. Some wobble in the average pitch is quite
common in vocal production. Then another consonant begins the A; again,
you can see the averaging graph doesn't begin until after the first
cycle of the pitch. This A starts 30 cents sharp and improves slightly
towards the end.
Those deviations from the center pitch look sort of
small in the graph, but remember the scale is much more compressed. At
the end of the box depicting the D, the pitch is now halfway to Eb,
right between the semitones. It is in fact quite out of tune. The other
notes aren't very accurate either, but this seems to be something we
have stopped listening to.
If your vibrato is even wider, you will need to
select View | Lower Graph Scaling to be 40 or 50.