quid pro quo vs transposing

quid pro quo

noun
  • Something which is understood as something else; an equivocation. 

  • An equal or fair transaction or series of process of exchange transactions; tit for tat. 

  • Something which is offered or asked for in exchange for something else. 

  • Substitution of one drug for another. 

  • A usually non-monetary exchange transaction, or series or process of exchange transactions. 

  • Sexual harassment in which a person in a workplace implicitly or explicitly requires sexual favours in exchange for something. 

transposing

noun
  • A transposition. 

adj
  • a musical instrument that is written in a different pitch to how it sounds, often for ease of playing multiple instruments of the same family that have different ranges. 

How often have the words quid pro quo and transposing occurred in a corpus of books? (source: Google Ngram Viewer )