This beautiful theater is located on the first floor of the historic Palazzo Montalto (now the College of St. Louis), so named in honor of Pope Sixtus V (note native of the village of Montalto), who founded it in the late 1500s and destined him to university college Marches for young people and remained so until the French Revolution. Following the Napoleonic suppressions, the palace passed to private ownership. Only in 1873 it became the seat of the college, formerly located in Via de 'Clear and known as the College of Nobles, by Barnabiti Fathers from 1773, the year in which they took over the suppressed religious order of the Jesuits. It 'very likely that the room currently used as a theater, it was only a private residence in the elegant hall for dances and receptions, where the balcony was used to accommodate the orchestra. however, it should be borne in mind that the Ricci mentions a "little theater up in the College Montalto", where in 1709 he recited work carnival, without specifying further. The need to have adequate space to exercise what may be defined as the exercise of the spirit pushed fathers Barnabites to permit the architect Francesco Gualandi the design of a real theater, to fit in the reception room of the new headquarters. The work was completed February 15, 1879. Theatre has a rectangular plan with a balcony continuous rim, supported by shelves with volute, which runs on three sides. On the short side, in front of the stage, it assumes the character of a lodge (which is enclosed in the gallery now no longer accessible), characterized by slender columns that support five round arches. The small stage, with trellises of the original, it is sufficient for the needs of the college, using this space for activities to support teaching, lectures, essays, theater workshop and occasionally for shows for charity. The eclectic decor consists of stucco and painted decoration is very rich and elegant, especially on the ceiling, where accented with three oval medallions with bouquets of flowers in the center and the allegory of Fame by the author Gardassoni by the parties along with pictorial William Minelli. Also the author of the curtain stained (in a precarious state of conservation), which depicts the encounter between Dante and Virgil, and the two figures of young men on both sides of the crest of the College (at the center of the band above the stage) Alexander Guardassoni, in which the theater was dedicated, appears to be in the nineteenth century Bolognese artist of undoubted interest. Finally, the terrazzo floor is the work of Constantine Diana and doors are painted walnut Antonio Sacchetti. (Lidia Bortolotti)