Housed in the foyer of the Municipal Theatre, the museum systematically recounts the historical events of the building, built according to a design by Lotario Tomba at the beginning of the 19th century on the site of two 18th-century theatres, the Cittadella, destroyed by fire in 1798, and the Saline, demolished in those same years due to its dilapidated state.

Among the exhibited documentation are the poster for the performance staged for the inauguration, which took place on September 10, 1804 with Zamori, ossia l'eroe delle Indie, a serious musical drama by Giovanni Simone Mayr, a sketch of the "secondino" painted by D. Menozzi in 1826, the watercolor figurines by L. Braghini for Annibale in Bitinia, dated 1821, and some memorabilia of Giuseppe Verdi and Luigi Illica. On the top floor, traditionally reserved for set designers, a large corridor was adapted in the mid-1970s to become an exhibition space. Here are kept photographs of artists and librettos of operas from the early 20th century that have gone out of the repertoire.