When the meter of a song (or poem) results in a word being pronounced with incorrect accentuation.
Whether this is intentional or unintentional, it's usually because the song was done by some foreigner who hasn't quite grasped the rules of stress in their second language, but sometimes they're just being completely incompetent about setting lyrics to music.
- The somewhat obscure Trope Namer, "Sing a Tropical Song," was written for the 1943 movie musical Happy Go Lucky. The Andrews Sisters also recorded it.
- In the second act of Wagner's Die Meistersinger, Sachs strikes his cobbler's hammer each time Beckmesser does this.
- The stirring aria "The Trumpet Shall Sound" from Handel's Messiah has the word "incorruptible" wrongly accented. This is usually corrected in performance, though the corrected version doesn't quite fit Handel's melody.
(I was the OP, but someone edited this page to get irrelevantly pedantic about how Boba Fett's name is supposed to be pronounced.)