Puccini has penned a note of thanks on the front of his understated calling card, offering his best wishes to fellow Italian musician Guglielmo Andreoli.

Guglielmo Andreoli (1862-1932) was a musician of many talents: he taught harmony, counterpoint, and piano at the Milan Conservatory, he composed in a variety of genres, he produced Italian editions of works by Beethoven, Mendelssohn, Weber, and Chopin, among others, and he co-authored a textbook on harmony. His eminent musical family also included his elder brother, another pianist named Guglielmo, with whom he is sometimes confused.