Grünewald was a successful opera singer (he sang bass in many Hamburg productions) and held important positions are various German courts. When he died in 1739, the composer Christopher Graupner (his colleague in Darmstadt) destroyed most of Grünewald's music, according to an agreement they had apparently made. Only seven keyboard partitas are known to have survived to modern times.
The videos were kindly made by Kim Patrick Clow from Sibelius sound files; although the performances are therefore rather mechanical, we hope they give you an idea of the music.