Bach - Sonata No. 3 For Violin And Harpsichord in E Major BWV 1016

Hans von Bülow, the great pianist/conductor of the 19th century was the originator of the phrase the Three B's of music, Bach, Beethoven and Brahms.  Each of the three were highly gifted composers who composed in the music forms of their times. Each can be considered to be the culmination of their eras of their musical eras; Bach of the Baroque,  Beethoven of the Classical and Brahms of the Romantic. Such is the way humans try to categorize and make sense out of things, and it makes sense,  as far as it goes. But looking upon any of the three as a representative of their respective eras can overlook the very traits of their music that helped create the styles of music that came after them.

One of J.S. Bach's contributions to the 'new style' are the six Violin and Harpsichord Sonatas. To be sure, there were sonatas composed for solo instrument and keyboard before these pieces, but these sonatas specify the keyboard instrument 'harpsichord' instead of the usual 'basso continuo' or figured bass designation of the Baroque era.  A sonata for violin and basso continuo would be written in two staves, one in the treble clef for violin and the other in the bass clef. The bass clef would be played by a keyboard instrument that could fill in the harmonies according to a kind of musical shorthand consisting of numbers and symbols over the note heads. The actual single notes of the figured bass could also be played by a bass instrument such as a cello or other bass instrument.

Sonata for solo instrument and figured bass (or basso continuo)

This gave a certain amount of freedom to the keyboard player to fill in the harmonies, not only according to guidelines and harmonic rules but also according to their individual skill and taste.  Bach's sonatas for violin and harpsichord do away with the figured bass. The keyboard part is written out in full.

J.S. Bach Sonata for violin and harpsichord 

Many times these three completely written out parts form a type of trio sonata played by two instrumentalists, and with Bach's contrapuntal skill there are sections where there are more than three independent parts.

Bach's Sonata For Violin And Harpsichord No. 3 in E Major is in 4 movements and is in the 4 movement form of the sonata de chiesa of the time:

I. Adagio - A slow, contemplative, lightly ornamented melody is gently accompanied by the harpsichord.
II. Allegro - A bright, cheerful melody is first uttered by the harpsichord and is taken up by the violin.  The two instruments have a happy, short conversation punctuated by the bass in the harpsichord.
III. Adagio ma non tanto - This is a short passacaglia with the violin and right hand of the harpsichord weaving in and out over the repeated four-measure bass.
IV. Allegro - This movement has the first theme being in running sixteenth notes, the type of tune that seems to accompany itself as notes are heard at the top of the melody while the other repeated notes are lower in pitch. The second theme is in triplets and shortly gives way to the initial theme. The music runs itself out in a short span of time and the sonata ends.