The Blending of the Registers is the singer’s touchstone: he should, therefore, devote special care to smoothing over their inequalities, until he is able to sing all the tones in his compass without a noticeable break. The more obvious the difference between the registers, the more perseveringly should the pupil strive to blend them.

Method of Vocalization for Soprano and Tenor.

Auguste Mathieu Panseron (1796-1859)