Analyzing complete compositions promotes deep learning for undergraduate theory students (Alegant 2014). I present a pedagogical approach that features spiral learning (Lang 2016) through recurring engagement with a complete piece, or "touchstone," to which students apply each concept they learn during a course. For example, Theory II students explore second-inversion triads, motives, cadences, small forms, non-chord tones, diatonic seventh chords, and secondary function chords in Cécile Chaminade's Idylle (Op. 126, No. 1). I discuss criteria for effective touchstone pieces, suggest possible touchstone pieces for Theory I-III, and share my analysis of a piece I have used successfully with my students. As reflected by the repertoire I suggest, touchstone pieces provide opportunities to highlight work by composers from historically underrepresented groups (Hisama 2018; Palfy and Gilson 2018). Students who analyze touchstone pieces increase their understanding of music analysis by examining course concepts in the context of complete works of music.