ostinato

In music, an ostinato (derived from Italian: "stubborn", compare English: obstinate) is a motif or phrase which is persistently repeated at the same pitch. The repeating idea may be a rhythmic pattern, part of a tune, or a complete melody. Both "ostinatos" and "ostinati" are accepted English plural forms. Strictly speaking, ostinatos 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.
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Noun
1. a musical phrase repeated over and over during a composition
(hypernym) phrase, musical phrase
(hyponym) ground bass

n. ostinato, melody or phrase that is constantly repeated

adj. obstinate, stubborn, headstrong, self-willed, single-minded, determined, opinionated, persistent, obdurate, stiff necked, pigheaded

v. persist, insist

OSTINATO