compliment vs sing the praises of

compliment

verb
  • To pay a compliment (to someone); to express a favourable opinion (of someone). 

noun
  • An expression of praise, congratulation, or respect. 

  • Complimentary language; courtesy, flattery. 

sing the praises of

verb
  • to commend someone's attributes to others 

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