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

Watch: Lana Del Rey and Jack Antonoff cover Joni Mitchell’s 'For Free'.

Jack Antonoff appeared as a surprise guest during Lana Del Rey's set at the Newport Folk Festival this past weekend - accompanying Lana on the piano for stripped-back renditions of 'Mariners Apartment Complex' and a cover of Joni Mitchell’s 'For Free'.

Watch both performances below...