"Muss i denn" (German for "must I, then") is a German folk-style song in the Swabian German dialect that has passed into tradition. The melody and some verses of this song became widely known through Elvis Presley's adaptation "Wooden Heart" in 1960, as well as Joe Dowell's version in 1961, becoming one of the most widely known German songs ever.

"Muss i denn" is about a man who has to leave the woman he loves and vows to remain faithful until he is back to marry her.  It was early on considered a patriotic song. It also became popular among German merchant seamen as a capstan shanty, and has been played as a naval quick march since the days of the Imperial German Navy. 

Some "Muss i denn" versions were widely popularized in the 20th century; those interpreted by German-American actress Marlene Dietrich] and by French singer Mireille Mathieu and Greek singer Nana Mouskouri deserve mention. The latter also sings English words (though not a translation) to the tune, under the title "There's a Time".

Surrey Brass plays an arrangement of this tune made by Richard Bissill.