The concept of chiaroscuro (i.e. bright and dark) can be approached in many ways. Personally I prefer to approach it first from a phonation standpoint because the dark side of the balance can be misunderstood particularly when it is approached vocallically. Vowels are often approached in terms of space: Throat space, back space, sinus space, etc. Each of these space sensations are problematic because the most common ways of sensing them are based in relative malfunction.
1. Back Space: In my bass-baritone incarnation I relied greatly on sensations of backspace, as several of the teachers I had worked with talked about accessing this space. This sensation is however based on a lowering of the larynx resulting from a release of subglottal pressure through a slightly breathy phonation. The resulting sound is usual relatively hollow, lacking in brilliance, the bright side of the chiaroscuro balance. I have since avoided this kind of space. The back space serves to me as a sign of a slight breathiness. It sounds warm and soft-edged to the singer’s inner ear, but dull and lacking in presence to the outside listener.
2. Throat space: The space in the throat that results from lowering the larynx can occur in several ways: a) depression of the back of the tongue, b) a yawning sensation resulting from breathiness or c) a balanced lowering resulting from flow-phonation. The latter is the one we seek and this provides acoustic support to the lower harmonics in the spectrum giving the proper darkness.
3) Sinus/mask space: Some singers swear by nasal resonance. There are two nasal experiences: a) the first is actual nasality which is a result of several possible phonation problems that lead to an excessive opening of the velar port. Dysfunctional nasality is usually accompanied by loose phonation. The good part of sensations in the mask/sinuses is reflective of the “twang” (not nasality) associated with the narrowing of the aryepiglottic fold that is responsible for the singer’s formant. The latter, which we seek, includes good glottal closure as opposed to the breathy phonation in the former posture. Also, true nasality (the one we do not want) is accompanied with a dull sound. How dull the sound gets depends on how loose the phonation is that produces the nasality.
If we can keep one rule, it is the and rule: “Neither does the presence of darkness mean the elimnation of brightness nor does the presence of brightness mean the elimination of darkness.” The perception of light only occurs because of the existence of a lack thereof, as is the perception of darkness relative to our consciousness of the existence of light. In singing (as in Kung Fu, says my Sifu), bright and dark are balancing complements, not opposites.
By utilizing both the brilliant twang associated with full glottal closure and with resonance sensations in the mask and darker color associated with the lowering of the larynx from flow phonation, we can accomplish a proper chiaroscuro balance. So how does this relate to vowels? Quite simply, a vowel that is balanced in low and high harmonics can only occur when there is proper glottal closure and narrowing of the aryepiglottic fold to provide brilliance of the high harmonics and the glottal flow that allows the larynx to relax lower providing adequate space for support of lower harmonics. The balanced vowel, that is both bright and dark is the result.
In fact we must neither conceive of the vowel in an excessively wide way to achieve brightness nor an excessively deep way to achieve darkness. The brilliance occurs because of an efficient source tone combined with the ratio of the diameter of the erypiglottic fold to that of the vocal tract (the twang: at least a 1:6 ratio is necessary). Both of these aspects result from laryngeal function. Depth is accomplished from natural lowering of the larynx resulting from flow-phonation, also a laryngeal function. In essence, the concept of vowels should be natural, neither too spread or too rounded. The glottal function as explained above provides the brilliance and depth referred to as chiaroscuro.
Whether a coloratura or a bass, good vocallic balance is possible even where extreme modification is necessary. A balanced vowel requires first and foremost a balanced tone.
Here, the legendary bass, Kurt Moll sings very low and relatively high in his voice. From speech to singing there is no major adjustment. His lowest tones maintain a certain level of brilliance recognized in the vocallic quality. The top notes are not lacking in depth.
This particular performance of the second Queen of the Night aria is quite possibly the best in recorded history. The same balance in Diana Damrau’s speech is maintained in the singing. One could argue that the speech is a little “belty” but one could call this a healthy belt. Her speech is not what one expects of a coloratura, but it has an excellent balance of bright and dark. Her vowels are neither dull, lacking in brilliance nor strident, lacking in depth.
Having one’s personal sense of vocallic balance could be one of the greatest influences on a singer’s vocal coordination.