Carrie Hatler provides an interesting historical post "St. Agatha's Conservatory of Music and Art," on the Forgotten Minnesota website. The institution was founded in 1884 as St. Agatha's Conservatory and Convent by the Sisters of St. Joseph of Carondelet in St. Paul, MN. The convent housed sisters who were teaching in nearby parochial schools. The sisters hoped to be self-supporting and operated the conservatory as a way to earn money to support their convent.
St. Agatha's Conservatory relocated after 1908 to an impressive six story building built by the sisters on the southwest corner of Exchange and Cedar. Enrollment peaked at over 1,100 students in the early 1900's and then began a slow decline with the conservatory closing in 1962.