The Leipzig sacred cantatas will follow in 51 disks, pitched lower, like the secular works.
He considered his best work to be a sacred cantata for adult voices: "Saul, King of Israel."
In 1999 and 2000 Leusink recorded all of Bach's sacred cantatas within 15 months.
Förster's surviving works are mostly sacred cantatas for three voices, with two violins and continuo.
Major symphonic conductors have grown increasingly willing to leave Bach, and particularly his vast body of sacred cantatas, to specialists.
Apart from these sonatas, three sacred cantatas dating from the early 1690s have been preserved.
Some composers wrote sacred cantatas to be performed in the church services of these days.
He set out to perform all Bach's sacred cantatas, a mission which he completed in 1987.
This late work is the only Latin cantata among around 200 surviving sacred cantatas in German.
In total he wrote more than 300 sacred cantatas, of which approximately 200 survive.