front man vs instrumentalist

front man

noun
  • The lead singer in a musical group. 

  • A person acting as the public face of some other, covert group. 

  • striker, attacker, forward. 

instrumentalist

noun
  • One who plays a musical instrument, as distinguished from a vocalist. 

  • An adherent of instrumentalism. 

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