Mannheim school refers to both the orchestral techniques pioneered by the court orchestra of Mannheim in the latter half of the 18th century as well as the group of composers who wrote such music for the orchestra of Mannheim and others. The father of the school is considered to be Czech composer Jan Václav Antonín Stamic, generally known as Johann Stamitz.
The court of the Elector Charles III Philip moved from Heidelberg to Mannheim in 1720, already employing an orchestra larger than those of any of the surrounding states. The orchestra grew even further in the following decades and came to include some of the best virtuosi of the time. Under the guidance of Kapellmeister Carlo Grua, the court hired such talents as Johann Stamitz, who is generally considered to be the founder of the Mannheim school, in 1741/42, and he became its director in 1750.
The most notable of the revolutionary techniques of the Mannheim orchestra were its more independent treatment of the wind instruments, and its famous whole-orchestra crescendo.
Members of the Mannheim school included Johann Stamitz, Franz Xaver Richter, Carl Stamitz, Franz Ignaz Beck, Ignaz Fränzl, and Christian Cannabich, and it had a very direct influence on many major symphonists of the time, including Joseph Haydn and Leopold Hofmann. (Cannabich, one of the directors of the orchestra after the death of J. Stamitz, was also a good friend of Wolfgang Amadeus Mozart from the latter's visit to Mannheim in 1777 onwards.)
Johann Stamitz visited Paris, and the Mannheim school had an influence on the Concert Spirituel Sacred Concert since 1754. When Joseph Legros took over the Parisian concert series Concert Spirituel, the relationship with the Mannheim School flourished and the music of Haydn became extremely popular in Paris. Prominent concerts in Paris during the 1770s were the Concert de la Loge Olympique (Concert of the Olympic Lodge) and the Concert des Amateurs (Concert for the Fans) which may have been part of the Concert Spirituel.