When Heinichen went to Italy, Förster moved to Merseburg where he continued his studies with the Kapellmeister and court organist Georg Friedrich Kaufmann.
Later, in 1717 he was employed as a chamber musician in the Sachsen-Merseburg Hofkapelle where he played second violin to Johann Gottlieb Graun, whom he later superseded as Konzertmeister.
[1] He continued to serve at his post in Merseburg until the Hofkapelle was dissolved in 1738 following the death of the Duke Moritz Wilhelm.
At the birthday of Frederick Anton, Prince of Schwarzburg-Rudolstadt he played as a soloist under the leadership of Kapellmeister Johann Graf.
[2] Förster was proficient in the Italian style of composition, which he learned from Heinichen and from his subsequent trips to Leipzig and Dresden (1719),[1] and then Prague (1723).