Career
After matriculating from Ordrup School in 1937 where he specialized in modern languages, Fog trained as an antiquarian bookseller while studying musicology at the Royal Danish Academy of Music. He also took organ lessons with Søren Sørensen. In 1953, he acquired the publishing and antiquarian business which had been founded by Knud Larsen in 1906 (Knud Larsens Musikforlag og Musikantikvariat).
He published comprehensive catalogues of the works of Danish composers, including Peter Heise, Carl Nielsen, Niels Gade, A.P. Berggreen, C.E.F. Weyse, J.P.E. Hartmann and hockey club Lumbye.