Johann Christian Bach was a composer of the Classical era, the eleventh surviving child and youngest son of Johann Sebastian Bach. He is sometimes referred to as "the London Bach" or "the English Bach", due to his time spent living in the British capital, where he came to be known as John Bach.[1] He is noted for influencing the concerto style of Mozart.

Johann Christian Bach was born to Johann Sebastian and Anna Magdalena Bach in Leipzig, Germany. His distinguished father was already 50 at the time of his birth, which would perhaps contribute to the sharp differences between his music and that of his father. Even so, his father first instructed him in music and that instruction continued until his death in 1750. After his father's death, he worked (and lived) with his second-oldest half brother Carl Philipp Emanuel Bach, who was twenty-one years his senior and considered at the time to be the most musically gifted of Bach's sons.

He enjoyed a promising career, first as a composer then as a performer playing alongside Carl Friedrich Abel, the notable player of the viola da gamba. He composed cantatas, chamber music, keyboard and orchestral works, operas and symphonies.

Bach lived in Italy for many years starting in 1756, studying with Padre Martini in Bologna. He became organist at the Milan cathedral in 1760. During his time in Italy, he converted from Lutheranism to Catholicism and devoted much time to the composition of church music, including two Masses, a Requiem and a Te Deum.[2] His first major work was a Mass, which received an excellent performance and acclaim in 1757.[2] In 1762, Bach travelled to London to première three operas at the King's Theatre, including Orione on 19 February 1763. That established his reputation in England, and he became music master to Queen Charlotte. He met soprano Cecilia Grassi in 1766 and married her shortly thereafter. She was his junior by eleven years. They had no children.

By the late 1770s, his music was no longer popular and his fortunes declined. His steward had embezzled almost all his wealth and Bach died in considerable debt in London on New Year's Day, 1782.[3] Queen Charlotte covered the expenses of the estate and provided a life pension for Bach's widow. He was buried in the graveyard of St. Pancras Old Church, London.[1]