disc jockey vs shock jock

disc jockey

noun
  • A person who plays, and sometimes mixes, recorded music at nightclubs, dances, parties, or some other social event; and/or as a backup musician for spoken word, or hip hop performers. 

shock jock

noun
  • A deliberately offensive or provocative talk show host. 

How often have the words disc jockey and shock jock occurred in a corpus of books? (source: Google Ngram Viewer )