Trio sonata

The trio sonata is a genre, typically consisting of several movements, with two melody instruments and continuo. Originating in the early 17th century, the trio sonata was a favorite chamber ensemble combination in the Baroque era.
Basic structure.
The trio sonata typically consisted of three parts, two violins and continuo. However, the two violins could be substituted with pairs of flutes, recorders, or oboes. The third part, the basso continuo, has two components. First, it includes the bass line, which commonly was played by a bass viol, violone, violoncello, or bassoon. Second, it includes a harmony-producing instrument, such as a small organ, a harpsichord, or a theorbo. The (basso) continuo could be performed by two or more performers; a cellist to play the bass line and a harpsichordist or organist to focus on the harmonies. Because there normally are two people playing the continuo part, there are usually four players in all. This accounts for the title of Henry Purcell's second collection, "Ten Sonatas in Four Parts" (1697); his first publication "Sonnata's of III Parts" (1683) likewise included separate parts for cello and keyboard. From about the middle of the 17th century two distinct types of sonatas appeared: sonata da camera (chamber sonata) and sonata da chiesa (church sonata).
Composers, compositions and variant formats.
The genre originated as instrumental adaptation of the three-part texture common in Italian vocal music in the late 16th century. The earliest published trio sonatas appeared in Venice (Salamone Rossi "Il primo libro delle sinfonie e gagliarde", 1607) and in Milan (Giovanni Paolo Cima, Sonata a tre for violin, cornett and continuo in the collection "Concerti ecclesiastici", 1610).
Arcangelo Corelli.
Italian composer Arcangelo Corelli was one of most influential composers of the trio sonata. The published trio sonatas by Corelli are:
An additional collection of Trio Sonatas, for two violins, cello, and organ, was published as "Op. post." in Amsterdam, in 1714. Corelli's trios would serve as models for other composers well into the 18th century.
Johann Sebastian Bach.
German composer Johann Sebastian Bach is another notable composer of the trio sonata, but he was known for shying away from the traditional structure of the sonata. He typically played the three parts with fewer than three instruments. One part could be played by a violin and the other two parts could be played by a keyboard, or all three parts could be played on the organ.
Trio sonatas by Bach include: