hip-hop vs ragtime

hip-hop

noun
  • A form of popular and dance music featuring strong percussion and a powerful rhythm, usually accompanied by rapping. 

  • An Afro-American urban youth culture based on rap music, breakdancing etc. 

verb
  • To move by hopping or with a hopping motion. 

  • To perform hip-hop music. 

ragtime

noun
  • A musical form having a rhythm characterized by strong syncopation in the melody with a regularly accented accompaniment. 

  • A piece of music in this style. 

How often have the words hip-hop and ragtime occurred in a corpus of books? (source: Google Ngram Viewer )