Anton’s father was apparently also a cellist at Eichstätt (a prince-bishopric bordering, later in, Bavaria) and probably was his first music instructor. In 1754 Johann gained a position as second cellist in the Palatine Electorate (Kurpfalz)’s court orchestra, then Germany’s finest, commonly known after its residence as the Mannheim Orchestra, also the focal point of the so-called Mannheim School (qv). He studied further (probably counterpoint and harmony) with Johann Stamitz (qv), remaining at Mannheim until his death, aged twenty-six, and burial there.

A 19th Century dictionary quotes one of the legends arising from Fils’ early death and the lack of information about his life: alledgedly he died from his habit of eating spiders, assuring his shocked contemporaries they tasted just like strawberries.