Ward Virts Concert Series: CSM Choir and Chamber Singers. May 11, 3 p.m., College of Southern Maryland, Prince Frederick Campus, Room 119, 115 J.W. Williams Road, Prince Frederick. The CSM Concert and Chamber Choirs will round out the 2007-2008 season. The Ward Virts Concert Series is presented by Kaine Homes and CSM. Limited tickets are available. Free. 443-550-6000 or firstname.lastname@example.org. www.csmd.edu/Finearts.