What is obbligati?

Obbligati are musical parts that are essential to the composition and cannot be omitted without fundamentally altering the piece. They are typically found in classical music, especially in Baroque music.

In Baroque music, obbligati were often instrumental parts that were given a prominent role in the composition. They were typically written for a specific instrument and were intended to showcase the virtuosic abilities of the performer. For example, in J.S. Bach's "St. Matthew Passion," there are several obbligato parts, including a viola da gamba obbligato in the aria "Erbarme dich" and a soprano recorder obbligato in the aria "Aus Liebe will mein Heiland sterben."

In addition to instrumental obbligati, there are also vocal obbligati. These are typically found in operas and oratorios and involve a solo voice singing a highly melodic and ornamental part against the main melody. For example, in Handel's "Messiah," there are several vocal obbligati, including a soprano solo in the aria "Rejoice greatly" and a countertenor solo in the aria "O thou that tellest good tidings."

Overall, obbligati are essential parts of the composition that add depth, complexity, and virtuosity to the music.