By the Classical period (roughly 1750–1800), both the symphony and the concerto had acquired more definite meanings, and the "concerto grosso" had disappeared altogether. This led in the last decades of the 18th century to attempts to combine the two genres, such as those by composers of the Mannheim school. Johann Christian Bach (the so-called "London Bach" and youngest son of Johann Sebastian) was publishing "symphonies concertantes" in Paris from the early 1770s on. Mozart, acquainted with the Mannheim school from 1777 and probably aware of J.C. Bach's publications, put considerable effort into attempts to produce convincing "sinfonie concertanti". His most successful are the following: