Carl Philipp Emanuel Bach in the context of "Georg Philipp Telemann"

Johann Sebastian Bach (31 March [O.S. 21 March] 1685 – 28 July 1750) was a German composer and musician of the late Baroque period. He is known for his prolific output across a variety of instruments and forms, including the orchestral Brandenburg Concertos; solo instrumental works such as the cello suites and sonatas and partitas for solo violin; keyboard works such as the Goldberg Variations and The Well-Tempered Clavier; organ works such as the Schübler Chorales and the Toccata and Fugue in D minor; and choral works such as the St Matthew Passion and the Mass in B minor. Since the 19th-century Bach Revival, he has been widely regarded as one of the greatest composers in the history of Western music.

The Bach family had already produced several composers when Johann Sebastian was born as the last child of a city musician, Johann Ambrosius, in Eisenach. After being orphaned at age 10, he lived for five years with his eldest brother, Johann Christoph, then continued his musical education in Lüneburg. In 1703 he returned to Thuringia, working as a musician for Protestant churches in Arnstadt and Mühlhausen. Around that time he also visited for longer periods the courts in Weimar, where he expanded his organ repertory, and the reformed court at Köthen, where he was mostly engaged with chamber music. By 1723 he was hired as Thomaskantor (cantor with related duties at St Thomas School) in Leipzig. There he composed music for the principal Lutheran churches of the city and Leipzig University's student ensemble, Collegium Musicum. In 1726 he began publishing his organ and other keyboard music. In Leipzig, as had happened during some of his earlier positions, he had difficult relations with his employer. This situation was somewhat remedied when his sovereign, Augustus III of Poland, granted him the title of court composer of the Elector of Saxony in 1736. In the last decades of his life, Bach reworked and extended many of his earlier compositions. He died due to complications following eye surgery in 1750 at the age of 65. Four of his twenty children, Wilhelm Friedemann, Carl Philipp Emanuel, Johann Christoph Friedrich, and Johann Christian, became composers.

Chamber music is a form of classical music that is composed for a small group of instruments—traditionally a group that could fit in a palace chamber or a large room. Most broadly, it includes any art music that is performed by a small number of performers, with one performer to a part (in contrast to orchestral music, in which each string part is played by a number of performers). However, by convention, it usually does not include solo instrument performances.

Because of its intimate nature, chamber music has been described as "the music of friends". For more than 100 years, chamber music was played primarily by amateur musicians in their homes, and even today, when chamber music performance has migrated from the home to the concert hall, many musicians, amateur and professional, still play chamber music for their own pleasure. Playing chamber music requires special skills, both musical and social, that differ from the skills required for playing solo or symphonic works.

The Mass in B minor (German: h-Moll-Messe), BWV 232, is an extended setting of the Mass ordinary by Johann Sebastian Bach. The composition was completed in 1749, the year before Bach's death, and was to a large extent based on earlier work, such as a Sanctus Bach had composed in 1724. Sections that were specifically composed to complete the Mass in the late 1740s include the "Et incarnatus est" part of the Credo. It is structured in four major sections and scored for five soloists, a choir that is five-part in many sections and divided in the "Osanna", and a Baroque ensemble including brass and wind instruments.

In the legacy of his son Carl Philipp Emanuel Bach, it appears as the "Great Catholic Mass" (die große catholische Messe), referring to the fact that all parts of the Catholic mass are set to music.

The Bach family is a family of notable composers of the baroque and classical periods of music, the best-known of whom was Johann Sebastian Bach (1685–1750). There are surviving ancestors of the Erfurt Line, like great-great-great grandson of Frederich Leopold Bach or the daughters of Philip Frederick Bach, Susan Jean Weaver and Nancy Louis Hertzog Bach. A family genealogy was drawn up by Johann Sebastian Bach himself in 1735 when he was 50 and was continued by his son Carl Philipp Emanuel Bach.

St. Thomas School, Leipzig (German: Thomasschule zu Leipzig; Latin: Schola Thomana Lipsiensis) is a co-educational and public boarding school in Leipzig, Saxony, Germany. It was founded by the Augustinians in 1212 and is one of the oldest schools in the world.

St. Thomas is known for its art, language and music education. Johann Sebastian Bach held the position of Thomaskantor from 1723 until his death in 1750. His responsibilities included providing young musicians for church services in Leipzig.The Humanistic Gymnasium has a very long list of distinguished former students, including Richard Wagner (1813–1883) and many members of the Bach family, including Johann Sebastian Bach's son Carl Philipp Emanuel Bach (1714–1788).

Johann Christian Bach (5 September 1735 – 1 January 1782) was a German composer of the Classical era, the youngest son of Johann Sebastian Bach. He received his early musical training from his father, and later from his half-brother, Carl Philipp Emanuel Bach in Berlin. After his time in Berlin he made his way to Italy to study with famous Padre Martini in Bologna. While in Italy, J.C. Bach was appointed as an organist at the Milan Cathedral. In 1762 he became a composer to the King’s Theatre in London where he wrote a number of successful Italian operas and became known as "The English Bach". He is responsible for the development of the sinfonia concertante form. He became one of the most influential figures of the classical period, influencing compositional styles of prolific composers like Joseph Haydn and Wolfgang Amadeus Mozart.