Carl Emil Seashore (1866-1949)
Using phono-photographic recordings of musical performances and speech and psychophysic measurements on the perception of the vibrato, Carl E. Seashores' research on Vibrato at the Univerisity of Iowa is the most extensive research that has ever been done since the 1920's/30's.
Vibrato: a periodic pulsation involving PITCH, INTENSITY, and TIMBRE. The best singers average a semi-tone in width and an oscillation between 6-7 cycles per second.
In 1922, Schoen (who was a part of the Seashore team at University if Iowa) mapped out the parameters of vibrato. During the 1920's through 30's they studied vibrato in great depth. Schoen pointed out " what is natural in the vocal vibrato would be considered pathological in other musculatures.
Vibrato is the result of neuro-muscular periodicities observable not only in the voice, but other parts of the body. But as Schoen pointed out: when working out at the gym, ones muscles will shake to signal fatigue and tiredness. However, the laryngeal vibrato is the result of tension release between two muscles, taking turns in resting in order to not fatigue.
There are 5-6 muscles which contribute to vibrato production:
Of the Larynx:
- Intrinsic (Thyroarythenoid, Cricothyroid (pitch regulator), interarytenoids)
- Extrinsic (Hyoid muscles of Neck)
- Articulatory muscles
It is important to know that Vibrato is still not fully understood and that Seashore clearly did not like straight tone: " We shall find that musical beauty in the vibrato consists primarily of three elements (1) enrichment of tone, (2) flexibility of tone, (3) The expression of tender feeling through instability". He also said, "A stable tone is experienced as dead; an oscillating tone, in the right proportion, radiates life and warmth."
There needs to be more research done, but this is the most that has ever been done. Maybe someones dissertation? Not mine!!! That is for sure. More soon.... maybe.
A photograph of Seashore using his invention, the tonoscope.
The vibrato: (1) What is it?, Carl E. Seashore, The Psychology of Music
The vibrato: (2) What makes is good or bad?, Carl E. Seashore, The Psychology of Music
The vibrato: (3) How can we approach an ideal vibrato? Carl E. Seashore, The Psychology of Music
The Natural History of the Vibrato, Carl E. Seashore, Proceedings of the National Academy of Sciences, 12/15/1931 Vol 17, No. 12.
Vibrato by the Seashore, Stephen Austin, Journal of Singing, March/April 2016, Vol 72, No 4