get in on the act vs undertake

get in on the act

verb
  • To become involved in something. 

undertake

verb
  • To take upon oneself; to start, to embark on (a specific task etc.). 

  • To commit oneself (to an obligation, activity etc.). 

  • To pass a slower moving vehicle on the curbside rather than on the side closest to oncoming traffic. 

noun
  • The passing of slower traffic on the curbside rather than on the side closest to oncoming traffic. 

How often have the words get in on the act and undertake occurred in a corpus of books? (source: Google Ngram Viewer )