Expressive movement, created by students to demonstrate musical elements and artistry, provides a valid assessment opportunity for general music teachers. This purposeful movement, "plastique animée", was developed by Swiss composer, Émile Jaques-Dalcroze, in the early 20th century. "Plastique animée" can serve as a useful tool, allowing teachers to observe an authentic, artistic musical experience for assessment purposes. Rubrics are based on predetermined criteria involving music elements, creativity, and expression. Students can self-assess by viewing a video recording of the movement and answering questions about the "plastique animée" experience. This article explains "plastique animée" and the process of implementation; provides two rubrics for assessing expressive, purposeful movement; and lists self-assessment questions and procedures. By assessing both objective and subjective elements, teachers and students can receive beneficial feedback regarding how a student comprehends musical concepts and demonstrates expressivity.