I believe the 'Bada-BING' business was an ad-lib on the part of James Caan.
But I'm sure Caan read the book as part of his preparation to play the role; it can be assumed that witnessing his father's killing of Fanucci as a boy might have have played a role in the characterization of Santino.
Apple
A wise and frugal government, which shall leave men free to regulate their own pursuits of industry and improvement, and shall not take from the mouth of labor the bread it has earned - this is the sum of good government.
- THOMAS JEFFERSON
| 
