Originally published June 26 2020.
Angelina sounded somewhat different in her final AGT performance “Someone You Loved”, but I couldn’t quite put my finger on it at first. After listening to the opening verse quite a few times, I finally realized that Angelina pulled a “Heifetz” in her vocals!
Barely audible vibrato
Jascha Heifetz was arguably the greatest violin virtuoso of the 20th century. One of his most renowned techniques was the fast vibrato. In a study of his recordings, it was discovered that his highest average rate of vibrato was 7.7 Hertz – or 7.7 cycles per second in layman’s terms.
Heifetz sometimes played with a shallow vibrato so fast that it was barely audible, but it helped form a rich timbre unique to his style.

Jascha Heifetz. Photo: fineartamerica.com
Trembling sensation
Most singers apply vibrato to a long vowel and simply let their voices oscillate naturally. Natural vibrato is typically a semitone in depth and 3 – 5 Hertz in speed. In a fast-paced song like “Someone You Loved” however, most vowels are too short to accommodate natural vibrato.
What Angelina did instead was controlled bursts of shallow vibrato attached to the short vowels, which lent a “trembling” sensation to her voice. Indeed, this type of vibrato is called “tremolo” in the Italian opera.
You may get a sense of this technique by listening closely to these opening phrases – “save me”, “driving me crazy” and “somebody to heal”. By my rough reckoning, the fast and shallow vibrato applied to the vowels was 4 – 5 cycles in length, with speed of 7 – 8 Hertz.
Angelina is one of a select few true masters of vibrato among young singers. It is definitely not something that can be easily obtained – one can only imagine the amount of effort she put into it over the years to hone the technique to such sophistication.