08/23/2013 12:53 pm ET | Updated Aug 23, 2013

Flash Mob Opera At Chicago Grocery Store Delights, Confuses Shoppers (VIDEO)

Shoppers at a Chicago grocery store last weekend were caught off guard when a group of the store's employees suddenly broke out into song -- and, as these things tend to go these days -- cameras were there to capture the whole thing on video.

The employees at the Mariano's in Chicago's West Loop, of course, were actually singers. Specifically, those responsible for the flawless rendition of "Brindisi" from Verdi's "La Traviata" were singers from Chicago's da Corneto company.

According to the store, the performance was in honor of Mariano's three-year anniversary.