Guitar riff

In music, an ostinato [ostiˈnaːto] (derived from Italian: stubborn, compare English, from Latin: 'obstinate') is a motif or phrase that persistently repeats in the same musical voice, usually at the same pitch. Well-known ostinato-based pieces include both classical compositions such as Ravel's Boléro and popular songs such as Donna Summer and Giorgio Moroder's "I Feel Love" (1977) and The Verve's "Bitter Sweet Symphony" (1997).

The repeating idea may be a rhythmic pattern, part of a tune, or a complete melody in itself. Both ostinatos and ostinati are accepted English plural forms, the latter reflecting the word's Italian etymology. Strictly speaking, ostinati should have exact repetition, but in common usage, the term covers repetition with variation and development, such as the alteration of an ostinato line to fit changing harmonies or keys.

If the cadence may be regarded as the cradle of tonality, the ostinato patterns can be considered the playground in which it grew strong and self-confident.

Within the context of film music, Claudia Gorbman defines an obstinate as a repeated melodic or rhythmic figure that propel scenes that lack dynamic visual action.

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Wikipedia