Harmonic dictation is widely utilized in college and high-school music theory classrooms as a summative aural skills exercise. Nevertheless, many students struggle to notate the voices and harmonic functions of didactic examples and to apply these skills in other musical contexts. The Do/Ti Test is a listening technique that can enable students to quickly and accurately identify harmonic function of didactic and real musical examples of different styles and genres. Using this method, students identify harmonies holistically based on the presence of particular guide-tones, beginning with Do and Ti, which they sing or audiate while listening. The Do/Ti Test implements the guide-tone method, first described by Rahn and McKay in 1988, and extends the method to hearing sequences, secondary dominants, and diatonic and chromatic modulations. By singing guide tones, students begin to develop “symphonic hearing,” an active, responsive mode of hearing in which listeners make music along with a stimulus in order to better understand it.