Among the symphony's instrumentalists was the recipient of this photograph, cellist George Koutzen (1926-2009). Koutzen played with the NBC Symphony Orchestra and New York String Sextet, but is perhaps best remembered as the conductor of the Suburban Symphony in New York, a post he held for 13 years. He was also the son of the noted violinist Boris Koutzen.
Although not identified, this photograph is by Robert Hupka and is one of several that he made during Carnegie Hall rehearsals in the 1940's. Hupka, who was born in Vienna into a music-loving family, had joined RCA Victor in 1942 and was closely associated with the Toscanini rehearsals. From this special vantage point, he was able to make a large number of pictures of Toscanini, some without the Maestro even being aware of being photographed.