Obbligato

Obbligato is a musical term of Italian origin used to describe an instrumental or vocal part that is essential to the texture of a composition. Derived from obbligare, meaning “to oblige,” the word signals that a particular line or voice is not optional but an integral element of the music.

In practice, an obbligato part may be a solo instrument, such as violin, flute, or oboe, carrying a prominent melodic line in counterpoint with the vocal line or with the continuo. It contrasts with the continuo or accompaniment, which is more flexible and not required to be present in the same way. The obbligato line is usually written out by the composer rather than left to improvisation.

Historically, the term is especially associated with Baroque vocal music—arias, cantatas, and oratorios—where the singer is supported by an obbligato instrument that provides an important, sometimes virtuosic, melody. It remains in use in later periods to designate a non-optional, characterful part within ensemble textures.

In performance, the obbligato line is treated as an essential feature of the piece, with careful shaping and interaction with the other parts. The term can also apply to instrumental works in which a particular instrument has an obligatory melodic role, even when not tied to a vocal line.