(Jim Higgins, Milwaukee Journal Sentinel) The Bel Canto Chorus and Milwaukee Chamber Orchestra are making the “United We Stand” concert at 3 p.m. Sunday both a musical and a civic event.

Commemorating the “victims, heroes and first responders” of the terrorist attacks a decade ago, the musical groups will give a free, outdoor concert of Mozart’s Requiem and Barber’s “Adagio for Strings” at Cathedral Square Park.