A mad barber, unusual pie ingredients, mistaken identities, midsummer mischief and romance are themes in the Opera Theatre of St. Louis’s productions of Stephen Sondheim’s “Sweeney Todd” and Wolfgang Amadeus Mozart’s “Cosi Fan Tutti.” Docents from the Opera Theatre will discuss the plots, share behind the scenes insights, and highlight music from each of the productions at Covenant House on Tuesday, March 27 (“Sweeney Todd”), and on Tuesday, April 17 (“Cosi Fan Tutte”). Docent presentations will begin at 1:30 p.m. and will be held at 8 Millstone Campus Drive in the lower level of Covenant House II Apartments in the Milford & Lee Bohm Social Hall. The events are free and open to the public. For information call: 314-432-1610.