Throwing surprise performances at jazz clubs around the world seems to have become a tradition for Lady Gaga and Brian Newman. Mother Monster took the stage with her best friend's band at La Fontaine, the oldest jazz club in Copenhagen, Denmark, to play a set of jazz standards, which she had already sang earlier that night for a sold-out crowd at her show with Tony Bennett.

Watch Gaga thrill the audience at La Fontaine with a stunning version of Edith Piaf's "La Vie en Rose"...