coup de main - noun
\ˌkü-də-ˈmaⁿ
Definition of coup de main : an attack that achieves complete surprise.

Watch: Grace Potter and Conan covering 'Proud Mary' together live.

Grace Potter appeared on Conan this week to perform a cover of Creedence Clearwater Revival’s 'Proud Mary' with O’Brien himself, as well as the full-time active duty United States Air Force members of Full Spectrum.

Watch the performance below...