Female singers have a wide range of tone qualities available to them. For many classical as well as nonclassical singers, the upper octave of the vocal range is performed using what we colloquially call the 'head voice', which is produced by a combination of laryngeal configuration and resonance adjustment. With some small modifications, the tone quality of the upper middle, and even the middle voice can be produced so as to be perceived as consistent with this upper voice. In this and future articles we will explore how female singers who use the 'head voice' accomplish it in their various ranges.
The Resonance Transition into the High Range
As female voices ascend in pitch into the middle of the treble staff, the fundamental frequency of the sung note begins to approach the frequency of the lowest vowel formant, F1. This freqency varies by voice type, by vowel, and to a certain extent, by the technique of the singer. Generally, women with long vocal tracts, and/or who sing with low larynx, will have F1 at a lower frequency for a given vowel than those who have shorter vocal tracts, and/or who sing with a neutral or high larynx.
Additionally, some vowels have lower F1 than others. For example, the vowels /i/ (ee) and /u/ (oo) have lower F1 than /o/ (oh), /e/ (ay) and /a/ (ah).
These factors, taken together, determine the frequency of F1 for that singer for that vowel, using that particular technique.
Singing an upward scale on a single vowel, as the fundamental approaches F1 for that vowel, that harmonic becomes progressively more resonant, to the point that it is the very loudest in the voice. This is the first characteristic of the so-called female 'head voice': In the upper range, its loudest harmonic is the fundamental.
Some Spectragraphic Examples - Whitney Houston
This first example is of Whitney Houston, singing the highest note (on the vowel /u/ (oo)) in her performance of 'I will Always Love You' available on youTube at http://www.youtube.com/watch?v=HGC003Xz3CY Its in the section after the modulation (at about 3:40) and she sings this note several times.
Except for the instrumental components on the extreme left end, the five highest peaks in this are from Whitney's voice, and you can see that the first one (the fundamental) is quite a bit taller (louder) than all the rest.
Angela Gheorghiu - Top note on Puccini 'Un Bel Di'
This one is taken from the top Bb of this famous aria, at http://www.youtube.com/watch?v=PNKWzml7zlY as sung by Operatic Lyric Soprano Angela Gheorghiu.
I've labeled the fundamental, so that it can be seen even though there is clutter from the orchestra (they are playing fully Forte, and doubling her note),
Barbra Streisand - Who's afraid of the Big Bad Wolf
This one is from a very early recording of http://www.youtube.com/watch?v=m3SmmKtR8Bw. Here, she is singing the vowel /a/ (ah) on the B above the treble staff.Barbra's, and released on 'The Barbra Streisand Album'. The headvoice tone is heard, used in an almost mocking way, at about 1:56 in the recording at
'Head Voice' in the middle range
While it most commonly appears in the upper range, 'Head Voice' quality is not limited to there. For many classical singers (and also for nonclassical when singing softly), head tone is achievable in the middle and upper middle by managing a glottal closed phase somewhat less than 50%, and by using darker vowels. In a future article, I will write on the dynamics of this particular kind of vocalism.