tremolo vs waver

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). 

waver

noun
  • An act of wavering, vacillating, etc. 

  • Someone who specializes in waving (hair treatment). 

  • Someone who waves, enjoys waving, etc. 

  • A tool that accomplishes hair waving. 

verb
  • To sway back and forth; to totter or reel. 

  • To fluctuate or vary, as commodity prices or a poorly sustained musical pitch. 

  • To shake or tremble, as the hands or voice. 

  • To falter; become unsteady; begin to fail or give way. 

  • To be indecisive between choices; to feel or show doubt or indecision; to vacillate. 

  • To flicker, glimmer, quiver, as a weak light. 

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