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

Watch: Halsey and All Time Low perform 'Remembering Sunday' together live.

August 20, 2018 | by Shahlin Graves

Halsey joined All Time Low on-stage tonight in New York, to perform acoustic song 'Remembering Sunday' together live.

Can u believe I sang my favorite song with one of my favorite bands tonight ???? @AllTimeLow @ashleyophoto pic.twitter.com/KHzWgCM79N
— h (@halsey) August 20, 2018

iamhalsey: “I used to play “Remembering Sunday” at every coffee house I played when I first started out. Tonight I played it with the boys in NYC and it was a dream awake. thanks @AllTimeLow @/ashleyosborne” pic.twitter.com/ZuBjxOY7D5
— Halsey Updates (@HalseyInsider) August 20, 2018