This weekend's article is a comparision of the 'belt voice' production as used by female singers, the 'robust head voice' as used by Operatic tenors, and the male 'Rock' pharyngeal voice . These types of vocalism share some characteristics which make them similar to each other, but also have some characteristics which differentiate them. As I have done before, I will use spectragraphic analysis to assist in the understanding of how these voices can be compared and contrasted.
A first example: 'Top Line F', Belt and Robust Head Voice
The following spectragraph shows the harmonic content of two voices singing the F natural usually written on the top line of the treble staff, that is, the F at the upper range of both the belt and tenor voices (the F the octave and a perfect fourth above middle C.) The female singer, represented in blue, is Patti LaBelle, from a televised recording of "You'll Never Walk Alone" from Carousel , recorded in the mid-'60s. The tenor is classical tenor Nicolai Gedda, from a 1973 recording of "Credeasi Misera" from I Puritani.
As I have done with prior recordings, I have matched the volumes of first harmonic (H1) so that the relative intensity of the upper harmonics can be identified. With this matching, we see the following:
1) There are five strong harmonics displayed by both voices, and for both of the notes, the 3rd harmonic is the strongest. This gives the voices power and color. The relative intensity of the harmonics is approximately the same in both voices.
2) H1 and H2 are lower in intensity than H3, but strong enough to make the core warmth of the tone quality very solid.
3) The 4th harmonic is both voices is in within the 'red lines', the most senstive part of our hearing range.
4) The white trace sections are 'wider', indicating that Mr. Gedda's vibrato is as well. Ms LaBelle sang her note with almost no vibrato, so the peaks are very pointed.
A second example: Middle line B, Pop Belt and Rock Pharyngeal voice
This second spectragraph, which I have annotated for harmonic identification, is of two voices singing the B above middle C. The two voices are Robert Plant of Led Zeppelin, singing 'A whole lotta love', and Whitney Houston singing 'I will always love you', on a vowel approximating /a/. I have matched the fundamentals as before.
Robert Plant's voice is in blue, and Whitney Houston's is in white. The spectragraph shows the following:
1) With the fundamentals equalized, the loudest harmonic in both voices is H2, and approximately the same intensity in both. With fundamental matched, and H2 so similar, the core of the tone for both voices on this note is identical. H2 in both voices carries the bulk of the volume for both.
2) H3 in Robert Plant's voice is somewhat louder by comparison to Whitney Houston's, but for both it is louder than the fundamental, and the 2nd loudest harmonic overall for both as well. Recall that the 3rd harmonic (an octave and a perfect 5th above the fundamental) as an odd harmonic, adds color to the tone quality. The relative strength of this harmonic in Robert Plant's voice is helps us to distinguish his from Whitney's tone quality.
3) H4 for both voices is about equal, but H5 and H6 in Plant's voice are stronger than Whitney's. This may be the result of "Singer's Formant" in Plant's voice. H6 is particulary well situated, as it is not only strong, but within the sweet spot of hearing.
Example three: Broadway Belt, and Operatic Tenor
This one is a fun one. The following spectragraph is of two very famous singers, Ethel Merman (the quintessential broadway belter of the mid-20th Century) and Luciano Pavarotti, Operatic Tenor. Ethel is singing the last note of 'Theres no business like show business' from Annie, Get Your Gun, and Pavarotti is singing the last note of 'Celeste Aida' from Aida. As usual, for comparison I have equalized the strength of the fundamentals so that relative harmonic balance can be shown.
Can you tell which is which?
Without giving away yet which is which, the following can be observed:
1) With the fundamentals equalized, the Blue voice has a louder H2 than the White one, which makes the core of the tone quality just a bit brighter, but not much.
2) H3 in both voices is the loudest harmonic, so they both have the color this harmonic brings to the tone, with a small advantage for the White voice.
3) H4 for both voices is quite a bit softer than H1, H2 and H3, adding some brightness, but not much to both.
4) The higher harmonics have less energy in both voices, but overall the White voice has more than the Blue one, which gives it more ring.
5) Both voices have vibrato (as evidenced by the 'wideness' of the harmonics), with the Blue voice having just a little bit more than the White one.
Have you determined which is which? Scroll down a bit to learn....
Pavarotti is in White. Merman is in Blue :-)
In looking at these representative voices, there are some commonalities that we can identify for this pitch range:
A) In each voice type, the principal strength of the tone is in the 2nd and 3rd harmonic. The fundamental is often 4th or lesser in strength, meaning that other harmonics align more closely with the resonances of the vowels chosen than it does.
Some voices display presence of singer's formant, and others do not.
C) Each of the singers shows strong voice production characteristics, but not equal balances of resonance.