tremolo vs tremor

tremolo

noun
  • A variation in the volume of a note or a chord, evoking a tremor or quiver. 

  • The device in an organ that produces a tremolo effect. 

  • A rapid repetition of the same note, or an alternation between two or more notes. It can also be intended to mean a rapid and repetitive variation in pitch for the duration of a note. It is notated by a strong diagonal bar across the note stem, or a detached bar for a set of notes (or stemless notes). 

tremor

noun
  • A shake, quiver, or vibration. 

  • An earthquake. 

  • A rhythmic, uncontrollable shaking of all or part of the body due to partial muscle contractions. 

verb
  • To shake or quiver excessively and rapidly or involuntarily; to tremble. 

How often have the words tremolo and tremor occurred in a corpus of books? (source: Google Ngram Viewer )