Bach, Johann Sebastian (1685-1750 Germany)
J.S. Bach was the "representative" of Baroque music. He was a great composer and organist. He has composed a high number of pieces, and of all kinds. It is said that the only instrument for which Bach did not composed a concerto, is the piccolo. Although he introduced no new forms, he enriched the prevailing German style with a robust contrapuntal technique, an unrivalled control of harmonic and motivic organisation in composition for diverse musical forces, and the adaptation of rhythms and textures from abroad, particularly Italy and France (source: wikipedia.org).
During his lifetime, Bach was a famous organist but he was not so famous as a composer. His composing style was considered as "old fashioned". The great acceptance of his music began early in the 19th century and nowadays he is considered as one of the greatest composers ever.