This study investigated the mental representation of music notation. Notational audiation is the ability to internally "hear" the music one is reading before physically hearing it performed on an instrument. In earlier studies, the authors claimed that this process engages music imagery contingent on subvocal silent singing. This study refines the previously developed "embedded melody task" and further explores the phonatory nature of notational audiation with throat-audio and larynx-electromyography measurement. Experiment 1 corroborates previous findings and confirms that notational audiation is a process engaging kinesthetic-like covert excitation of the vocal folds linked to phonatory resources. Experiment 2 explores whether covert rehearsal with the mind's voice also involves actual motor processing systems and suggests that the mental representation of music notation cues manual motor imagery. Experiment 3 verifies findings of both Experiments 1 and 2 with a sample of professional drummers. The study points to the profound reliance on phonatory and manual motor processing--a dual-route stratagem--used during music reading. Further implications concern the integration of auditory and motor imagery in the brain and cross-modal encoding of a unisensory input. (Contains 3 figures and 11 tables.)