The earliest available information concerning Grauel's career is a mention of him working alongside his father-in-law, Johann Christian Hertel, at the court of the duchy of Mecklenburg-Strelitz in Neustrelitz at the time of the Hofkapelle's dissolution in 1753, when he was forced to search for employment elsewhere.
[2] After leaving Neustrelitz, Grauel was employed by Johann Nepomuk Gotthard Graf von Schaffgotsch in Berlin.
Most notably, Charles Burney, after his visit to Berlin in 1772 wrote: "M. Grauel, a violoncello performer in the King’s band, played a concerto; it was but ordinary music; however, it was well executed, though in the old manner, with the hand under the bow.
"[4] On the contrary, his compositional skill was mentioned favourably by two contemporary commentators, Ernst Ludwig Gerber: "He is said to be a skilled and competent performer and composer for his instrument"[5] and Johann Adam Hiller: "[Grauel] plays his instrument very well and sets beautiful concertos and solos for it.
It seems that some confusion arose due to the similarity of the name 'Grauel' to his contemporaries Johann Gottlieb and Karl Heinrich Graun, also musicians at the Berlin court.