Nothing could have afforded a finer hearing of the quality and the compass of her voice, and she knew of old how well it suited her; yet at the outset, from the sheer excitement of her suspicion, Hilda Bouverie was shaky to the point of a pronounced tremolo.
"Stingaree"
E. W. (Ernest William) Hornung
Little off key and your voice won't set the world on fire, and it has a tremolo quality that may be rotten-bad singing, but it's the right stuff for the act.
"Star-Dust A Story of an American Girl"
Fannie Hurst
Sufficient investigations have not been made to make the matter certain, but tremolo, trembling of the vocal organs, and muscular stiffness, or unnatural tension, seem to go together.
"Resonance in Singing and Speaking"
Thomas Fillebrown