What was basso continuo in Baroque chamber music?

In Baroque chamber music, basso continuo (also known as thorough bass or figured bass) was a system of partially improvised accompaniment built upon a written-out bass line.12

This practice typically involved two types of performers:
* A keyboard or chordal instrument: An organist, harpsichordist, or lutenist would realize the harmonic implications of the bass line. To guide this, composers often provided "figures"—a musical shorthand placed above the bass notes that indicated the required intervals and chords.123
* A low melody instrument: An instrument such as a cello, viola da gamba, or bassoon was used to reinforce the bass line.123

Basso continuo was fundamental to the Baroque era, allowing performers to exercise spontaneous improvisation while providing a steady harmonic foundation for the music. By contracting the harmonic substance of a composition into the hands of the keyboard player, it offered a flexible alternative to the rigid polyphony of the Renaissance, giving the performer significant leeway in how they realized the harmonies.134