"Innsbruck, ich muss dich lassen" ("Innsbruck, I Must Leave You") is a German-language song written by Heinrich Isaac (1450–1517). It is famously associated with the city of Innsbruck in Tyrol (in modern-day Austria). The lyrics express sorrow at having to leave a post at court. There has been doubt whether this melody was in fact written by Heinrich Isaac or copied from earlier tunes. The melody was later used in a Lutheran chorale, "O Welt, ich muß dich lassen".