A prepared account or speech aimed at persuasion, apology, advocacy, wheedling, etc: A flimsy excuse or transparent lie is called ''a song and dance''/ Some bum will brace you with a long song of utter inconsequence(1895+)
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with song and dance
song and dance
An elaborate story or effort to explain and justify something, or to deceive and mislead someone. For example, Do you really believe his song and dance about the alarm not going off, being stopped for speeding, and then the car breaking down? or At every annual meeting the chairman goes through the same song and dance about the company's great future plans. This term originally referred to a vaudeville act featuring song and dance.
[ Late 1800s