Krzysztof Penderecki's Threnody to the Victims of Hiroshima (1960) is often considered separately from, or as an alternative to, serialism. Most scholars focus on texture or density in this work, without mention of the texture's serial organization. Those that do consider serialism in Threnody focus on the serial organization of specific pitch classes, like the twelve-tone canon in the second half of the work. I will demonstrate the serial organization of elements besides pitch classes in the first half of Penderecki's Threnody to inform our understanding of the piece as an experiment in mixing serialism and texture-based composition. Serial organization in this piece includes relationships among contour segments and sets of percussive elements based on the operators of retrograde, multiplication, rotation, and transposition.