simultaneity vs synchronization

simultaneity

noun
  • The quality or state of being simultaneous; simultaneousness. 

  • More than one complete musical texture occurring at the same time. This first appeared in the music of Charles Ives, and is common in the music of Conlon Nancarrow, and others. 

synchronization

noun
  • The state or property of being synchronized. 

  • The arrangement of military actions in time, space, and purpose to produce maximum relative combat power at a decisive place and time. 

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