Indeed, the riff—in essence, a repeated motif over changing harmonies, sometimes given a syncopated kick through a displacement caused by a contrast between the length of the phrase and the underlying meter—may have been the undisputed musical signature of the era (as witnessed by the success of “Opus One,” “In the Mood,” “A String of Pearls,” “Flying Home,” and other like numbers), but apparently no one had told Ellington.
