What do you understand by Google Dance?
 

Google Dance happens when significant overhauls happen on the database kept up by Google. Steady rearranging prompts to unsteady rankings of the Web Pages.This proceeds for some days and is known as Google move.

In search engine optimization (SEO), Google Dance is an out-dated slang term used to describe the period of time in which Google used to rebuild its rankings, and as a result of this rebuilding, rankings of Web sites on Google's SERP may fluctuate in order during the several day periods. The "Google Dance" would happen anywhere up to 36 times per year, however in 2003 Google begun updating its index on a weekly basis, which all but eliminated the Google Dance.

Source : http://bit.ly/2fYM8ab