The interior has maintained the original Romanesque Greek cross plan, with a nave and two aisles divided by
piers and ending with an apse, but the decoration its largely from the 17th century Baroque renovation. On the walls are tapestries, partly executed in
Florence (1583–1586) under
Alessandro Allori's design, partly of Flemish manufacture, depicting the
Life of Mary. Over the tapestry of the
Crucifixion (executed in
Antwerp on Ludwig van Schoor's cartoons, 1698) is a painting by
Luca Giordano, with the
Passage of the Red Sea (1691). Left to the entrance is the sepulchre of Cardinal Guglielmo Longhi, work by Ugo da Campione (1313–1320). At the beginning of the left aisle is the Baroque confessional carved by
Andrea Fantoni in 1704. A crucifix from the 14th century is on the presbytery's
balustrade. On the rear wall are the tomb of the composer
Gaetano Donizetti, by
Vincenzo Vela (1855) and that of the latter's master
Simone Mayr (1852). Mayr established the
Bergamo Conservatory at the Santa Maria Maggiore in 1805, and the church operated the school until it became an independent institution in 1908. Donizetti was an early pupil at the conservatory. In the presbytery itself, housing six bronze candelabra from 1597, is a wooden choir designed by
Bernardo Zenale and Andrea Previtali. The reliefs with Biblical tales were executed in 1524–1555 on designs by
Lorenzo Lotto. They are characterized by a polychrome effect rendered through the use of different wood types. The right transepts has
Giottesque frescoes from an unknown artist, with
Histories of St Aegidius,
The Last Supper and the
Tree of Life (1347), partially covered by a 17th-century fresco. ==References==