A couple years ago DePaul musicologist Enrique Arias, president of the early-music ensemble Ars Musica Chicago, learned that thousands of old manuscripts survived in the archives of the Basilica of the Virgin of Guadalupe in Mexico City. While most early-music scholars focus on pre-Baroque western European works, Arias specializes in the musical cultures of Spain’s American colonies; after perusing some of the scores, he started planning a concert that would approximate a service held at the basilica in the late 18th century. The site of the church has been sacred to Catholics since 1531, when the Virgin of Guadalupe appeared there to an Indian named Juan Diego; within six years more than six million Aztecs had accepted Catholicism. For many the Virgin has come to symbolize Mexico’s hybrid of native and Spanish Catholic cultures; first the Vatican named her the protector of New Spain and its Indian peoples, and in 1810 she was adopted as an emblem of Mexican independence. Arias’s program in her honor includes two motets in Nahuatl languages, paraphrased from the original Latin in the late 1500s to aid in the conversion of indigenous peoples. Also featured are three motets from the basilica’s archives, all still in Latin: the first, a magnificat from the 1760s by Ignacio Jerusalem, an Italian who became a chapel master in Mexico, sounds remarkably like Pergolesi; little is known about the other composers, Mariano Mora (“Beatus vir”) and Francisco Maria Campuzano (“Domine probasti me”), except that they were born in Mexico–and that their works sound no less Italian for it. Musicologist and harpsichordist Lidia Guerberof Hahn, who lives in Mexico City and found the manuscripts Arias has drawn from, will play a group of unattributed keyboard sonatas reminiscent of the work of Spanish composer and friar Antonio Soler. Rounding out the bill are a short overture for strings from the basilica’s collection–noteworthy because it proves the church had an orchestra, not just a choir–and three Gregorian chants, medieval in origin but often sung in Mexico. Ars Musica’s seven-voice chorus includes respected bass-baritone Andrew Schultze, also the group’s artistic director; joining the singers will be organist Robert Finster and members of the Chicago Baroque Ensemble, including David Schrader on harpsichord continuo. Stephen Blackwelder conducts. Saturday, 7:30 PM, St. Vincent de Paul Church, 1010 W. Webster; 312-409-7874. A symposium on the Virgin of Guadalupe’s importance to 18th-century Mexican culture will be held at 10 AM on Saturday at DePaul University’s Cortelyou Commons, 2324 N. Fremont.

Ted Shen