Herman Klein (1856-1934) in New York City c. 1901 

In the old Italian school of singing nothing used to be more admired and cultivated than an absolutely steady tone. To-day even in Italy a strong vibrato or a quivering tremolo is generally preferred. Consequently, the modern Milanese 'maestro' encourage it. 

Whether a trembling tone can ever furnish a satisfactory medium for the singing of Mozart is another question. We have evidence, both internal and external that the voices for which Mozart wrote did not suffer from this particular drawback. The sin did not become common until some years after it had started at the Paris Opéra in the midway of the last century Meyerbeer, Auber, and Gounod openly expressed their detestation of it. In alliance either with a strain of pure melody or a declamatory passage, a trembling voice, no matter how pleasing its quality per se, has always sounded disagreeable to the ears of an English audience. 

Intelligent use of the method of breathing described above practically obviates all danger of an unsteady tone. Instinct for the exactly right amount of breath-pressure should be natural to the good singer and made reliable by practice and experience. It contributes, moreover, to the liquid purity and clearness of timbre resulting from an undisturbed adjustment of the vocal cords. 

This economy of breath and this adjustment are interdependent, since the muscles of the throat respond and resist automatically in exact proportion to the varying degrees of pressure from the lungs. Yet the need for care does not end there. The singer intent upon the tone must not think of the throat, but of where and how the tone itself is reflected or placed: that is the true point d'appui. It follows that a perfect sostenuto can only be obtained when the singer has the sensation of direct and uninterrupted great support extending from the region of the diaphragm to the area of resonance. 

—From The Bel Canto: with particular reference to the singing of Mozart (1923) by Herman Klein. (The complete text can be found in Herman Klein and the Gramophone (1990), a collection of essays which can be accessed by clicking on the link.) 

Readers of Herman Klein and the Gramophone can learn quite a bit about his thoughts on vibrato, which is what I did by going to the link above, using the "search" feature on the left-hand side of the screen, then pulling down my hard copy edition from the shelf.

Type in "vibrato," and you will find twenty-five citations within Klein's text. What does one learn? Well, for one thing, it becomes clear that Klein thought of vibrato in a negative context, that is, he observed its aural character to be at variance to the normal vibration found in the singing voice. This is made clear in the citation appearing on page 221. 

Another warning—addressed this time the English male soloists. They are too much out for volume. Perhaps it is because they are mildly jealous of the foreigner, with his bigger voice and freer production. Anyhow, their tone sounds a great deal louder on the gramophone than it does as a rule in the concert-room or even in the opera house. They appear to be standing quite close—much too close—to the microphone, and, by using excessive breath-pressure, they either detract from the natural beauty and purity of their voices or else they set up a vibrato which is not a normal feature of their singing. In this matter, as I think I have observed before, the microphone is more relentless than a highly-polished mirror. It shows up every defect to which the human voice is liable; and I regret to add that the habit of making the tone unsteady by careless or unskillful breathing is one of the commonest of those defects.

Excessive preath-pressure? Well that makes sense, don't you think? Klein also attributes "vibrato" to breath-pressure on page 452 when referring to

Tancredi Pasero's singing. 

The bass delivered the broad theme of King Henry's Prayer, and from the lips of Tancredi Pasero it sounds very broad indeed, despite the rapid vibrato of his (due to excessive breath-pressure) which is his only serious fault. Otherwise, he is in the front rank of Italian "singing basses."

Fortunately, we are able to hear just what Klein was referring to at Youtube! Click on the link here, and you will hear Pasero sing the very recording Klein reviews.

By way of comparison, Klein has nothing but good things to say about Titta Ruffo's singing on page 79, where he reviews Ruffo's rendition of the Prologue from Leoncavallo's I Paglicacci. Listen to it here.

It is a magnificent organ, properly produced, amazingly resonant, free from nasality or vibrato, and controlled by true diaphragmatic breathing. The power and opulence of the tone strike the listener from the instant he sings the "Signore, signori"; and you can even—rare event! —catch the hissing of the "s" as well. In each successive phrases there is an abundance of expression ample contrast, and not a hint of exaggeration. To teachers who use the gramophone I would say, "Here is your perfect model!" I may even add my opinion that this is how Santley in his prime would have sung the Paglicacci Prologue. And praise can go no higher than that.

What does one hear in Ruffo's singing?

A vibrating tone, which is quite different than Pasero's vibrato.

One also hears the sostenuto which Klein refers to in Bel Canto, which he considers a matter of correct production, one requiring steadiness.

We can take from this that Klein's sostenuto does not mean straightened tone, which, by its very nature is limiting to vocal function. In short: steady does not mean straight! 

Others are welcome to disagree, but if we take Klein's teaching as having descended from a direct line of voice teachers stretching back to Nicola Porpora (Klein's teacher was Manuel García, who's own father—also Manuel—studied with Giovanni Anzani—a student of Porpora), then we will want to review Baroque performance practice, which has been straightening out vocalists and orchestras since the 1960's.

Happily, the whole matter seems to be under revision. Click here

 for another perspective.

Note: January 20, 2016: Alert readers will know that Klein taught that the "true point d'appui" was the "mask," a controversial concept that is dealt with in-depth in the introduction and text contained in Hidden in Plain Sight: The Hermann Klein Phono-Vocal Method Based upon the Famous School of Manuel García.

Contact Daniel Shigo for voice lessons in García’s method of singing, both in New York City and online.