Johann Sebastian Bach
Johann Sebastian Bach (1685 - 1750) was a central figure of the Baroque period. He was a German composer, harpsichordist, organist, and organ builder.
Bach was best known for his keyboard works and church music. Some of his most notable keyboard works include the Well-Tempered Clavier, Goldberg Variations, and Art of Fugue, which was unfinished at his time of death. Bach’s sacred works include Mass in B Minor, St. Matthew Passion, chorale preludes, and over 200 cantatas.
J.S. Bach was known for his innovative use of counterpoint and complexities in his compositions. In his church jobs, he would harmonize hymn tunes so freely that the congregation could not sing along. Bach was also known for concealing religious and numerological symbols into his music. For example, in the St. Matthew Passion, the singers ask "Lord, is it I?" 11 times to signify the 11 disciples, excluding Judas.
Here is an excerpt from Bach’s (Little) Organ Fugue in G minor.