The interior owes much to Corrado Parducci, a sculptor born in Italy in 1900 and brought to Detroit by Albert Kahn. Mason first declined to hire him because he was only 24, but Parducci won him over with models of his ideas, and the temple became his first solo commission. He designed much of its interior stone, plaster, and metalwork, including plaster ceilings and light fixtures. He worked from small sketches that became full-size clay models, which foundries cast in bronze or aluminum, and he never carved the stone himself. He went on to complete about 600 commissions, among them churches, schools, banks, and utility buildings. The temple has seven craft lodge rooms, each in a different style, with motifs from Egyptian, Doric, Ionic, Corinthian, Italian Renaissance, Byzantine, Gothic, and Romanesque design. Italian artists carried out the work under Mason’s direction, and the Detroit Historical Society says the rooms range from Corinthian to Art Deco.
The building is also a working venue. Its Masonic Temple Theatre seats about 4,400, after nearly 600 of the original 5,000 seats were removed because of poor sightlines, and its stage is 100 feet wide and 55 feet deep. From 1936 to 1942, the Detroit Symphony Orchestra broadcast the Ford Sunday Evening Hour from the auditorium on radio, with free admission and stations across the country carrying the program. Early Detroit auto shows were held in the building, Michigan Opera Theater staged productions on its stage, and Jascha Heifetz, Jimi Hendrix, and B.B. King later performed there. The former Scottish Rite Cathedral seats about 1,600, the Fountain Ballroom covers 17,264 square feet, and the drill hall measures 160 by 100 feet and has a floating floor laid on felt cushions, which hosts trade shows and Detroit Roller Derby. The temple has five pipe organs and seven stained-glass windows.