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Sunday, August 26, 2018

Good Vibrations

Vibrato, technically "a periodic change in pitch," is standard practice for classical violin. So much so that playing without vibrato is considered a special instruction to the musician. Traditional fiddle music and early music performance may omit the vibrato -- there is lively debate on the subject!

Violin vibrato is physically achieved by rolling the pad of the finger along the string -- towards the scroll, properly, so pitch is lowered. The performer accomplishes this roll by rotating the hand backwards at the wrist, or by moving the hand and forearm as a unit, or by a combination of the above (depending on speed, taste, depth, position on the fingerboard, and so forth).

On guitar and bass the wrist rotates in order to vary the position on the fretboard and thus change the pitch. There is another technique, however, and that is bending; the performer pushes or drags the string sideways whilst remaining on the same fret. This increases the tension thus raising the pitch. Bending is usually slower and more dramatic. Standard practice is to bend an accurate half-tone -- instructors get annoyed at students who can't consistently hit their pitch on a bend.

In singing, vibrato comes from the vocal chords but there is also a related pulsation that comes from the diaphragm. Essentially, vocal vibrato is a pitch change and has a higher periodic frequency, whilst diaphragm motion produces a slower change that is predominately volume. The two interact, giving a wide variety of tonal colors (and as well a wide variety in the ability of the singer to find and stay on their pitch, or to, as the detractors would have it, to attempt to disguise their failure.)

The recorder and tin whistle both respond to diaphragm vibrato, although it is considered non-traditional on the latter instrument. In addition they can practice something that is better called a trill; a fast fingered change of note. Unlike the other examples, a trill if not indicated otherwise is performed above the written note. The tin whistle adds an interesting idiomatic variant; on notes higher on the body of the instrument, a finger can be flicked over but not touching a lower finger hole, thus providing a subtler (and rapid) pitch shift.

There are many possible ways to execute these sorts of variations and color on the brass and single-reed families. I have found on the soprano saxophone (or, rather, the Yamaha Venova) diaphragm vibrato provides interest, fast finger trills are more than possible, but there is also a unique technique that involves small changes to the size and shape of the mouth cavity and shape and pressure of the embouchure by moving the jaw in a regular fashion.

Diaphragm vibrato is difficult to control especially at speed and is best suited for deep slow volume shifts during long sustained notes. The "lip trill" is fast and easy to employ and changes of speed and depth are extremely easy.

On the trumpet, a similar approach is used. Different players have approached this in different ways, from a jaw motion similar to that used on the single-reed (my current approach) to physically shifting the instrument against the performer's face. There appears to be at least one school out there that teaches holding down a valve and wiggling the finger on it as if it were a guitar string; the result, one presumes, being to shift the trumpet in and out of the selected embouchure and thus create a change of tone and/or pitch.

The trumpet of course has a variety of techniques to similar ends (many shared with the saxophone), such as the shake, the growl, flutter tongue (possible on single reed if you are careful), and -- a trumpet particular -- rapidly shifting between alternate fingering of the same note.



Vibrato adds color and interest and an additional expression to notes you want to give prominence. It can provide an emotional swell within a held note that is otherwise kept at a stable pitch and volume.

The downside? Once you learn how to do it (getting to arm vibrato on the violin is a good year's work), it is very, very hard not to use it all the time.


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