This was the next-to-last completed MGM film under Louis B. Mayer's supervision (the last was Show Boat (1951), released in the summer of that year). A proxy fight soon after would see him removed as the head of the studio he helped to found. He was replaced by his former chief of production, Dore Schary. Mayer ran MGM for 27 years, Schary for barely 6.
Jesse L. Lasky, who served as associate producer on this film, also knew the real Enrico Caruso. In 1918, whilst serving as the head of Famous Players (later Paramount) Studio, Lasky had paid Caruso to star in two silent films, My Cousin (1918) and The Splendid Romance (1919), neither of which was commercially successful.
Included among the American Film Institute's 2006 list of 180 movies nominated for AFI's Greatest Movie Musicals.
Conductor Richard Hageman, who played Carlo Santi in the film, actually knew Enrico Caruso and led several performances with him at the Metropolitan Opera, including the 1918 War Relief Benefit re-created in the film.
In Caruso's day the NYC Metropolitan Opera House occupied an entire block on Broadway halfway between Times Square and Macy's Herald Square. It was vast (3625 seats) and what Caruso sees peeking out from behind the curtain was the actual interior. The new Metropolitan House is vaster (3800 seats) though Radio City Music Hall from 1932 was even vaster (5960 seats).