Antoinette Sterling and The Middle Voice

Though she was known as an English ballad singer, Antoinette Sterling was born in America. Originally a student of Carlo Bassini in New York, Sterling went to Europe to study with Manuel Garcia and the famous Centenarian's sister Pauline Viardot-Garcia.  She also had lessons with the renowned Garcia exponent Mathilde Marchesi.  Her voice?  A pure clear contralto which excelled in German Lieder, Oratorio and music which displayed depth of feeling.

Antoinette Sterling's first lessons with the great maestro saw her being upbraided for singing in all of her range- a full three octaves. 

Until the American vocalist commenced her training under him she used the full extent of her voice, singing from the D below middle C to the top soprano C sharp, a range of three octaves. She sang all the contralto arie from opera and oratorio, and at the same time felt equally at home with the soprano roles.

The first thing that her new master did on hearing her was to make the remark, " If you continue as you have been doing, do you know what will happen ? Look at this piece of elastic. I take it firmly at the two ends, and stretch it. What is the result ? It becomes thin in the middle. If I were to continue constantly to do this, it would get weaker and weaker, until finally it would break. It is thus with the human voice. Cultivate an extended range, and keep on singing big notes at both extremes, and the same thing will occur which we have seen with the elastic. Your voice will gradually weaken in the middle. If you persist in continuing long enough, it will break, and the organ be rendered useless." For this reason he strongly advised her to abandon the higher notes, confining herself to genuine contralto music. Moreover, with the reduced range, he told her strictly to avoid practising on the extremes, to use them as little as possible, and build up her voice by exercising the middle portion of it. It is an invaluable hint for all singers. His pupil realized the wisdom of what he said, and from that time onwards ceased to use the top half octave of her voice.
From Antoinette Sterling and other celebrities by Malcom Sterling Mackinlay, p 177-178 

What leaps out at me in this passage is Garcia's keen ear which told him that Sterling's voice was not that of a soprano, but rather, a contralto.  How might have he discerned this?  By listening to Sterling's middle voice, it's depth of tone and color.   It is here that problems first appear, not in the extremes of the voice.  Take care of the middle and one takes care of the low and high range?  It would seems so.

Sterling's son, Malcolm Sterling Mackinlay, wrote his mother's and Manuel Garcia's biography (Antoinette's is quite entertaining), and had the distinction of being one the last students undergo Garcia's four-year course of study.