 Diemer is a keyboard performer and over the years has given concerts of her own organ works at Washington National Cathedral, The Cathedral of Our Lady of the Angels in Los Angeles, Grace Cathedral and St. Mary's Cathedral in San Francisco, and others.Works include many collections and single pieces for organ as well as many for solo piano, piano 4 hands, and two pianos.Her major chamber works include a piano quartet, string quartet, two piano trios, and sonatas and suites for flute, violin, cello, and piano as well as settings of the psalms for organ with other instruments.