ostinato

In music, an ostinato (derived from Italian: stubborn, compare English, from Latin: ‘obstinate’) is a motif or phrase that persistently repeats in the same musical voice, frequently in the same pitch.

Well-known ostinato-based pieces include both classical compositions such as Ravel’s Boléro and the Carol of the Bells, and popular songs such as Donna Summer and Giorgio Moroder’s I Feel Love (1977).

Ref. https://en.wikipedia.org/wiki/Ostinato