The tritone paradox is a musical illusion consisting of pairs of octave-ambiguous tones that could be heard as ascending or descending in pitch. This study investigated whether perception of the tritone paradox can be unconsciously influenced by a masked visual prime – specifically, a musical notation. In Experiment 1, participants were first given a “neutral” masked prime (an image of an empty music staff) to assess baseline perception. Then, they were presented with a “meaningful” masked prime consisting of two music notes arranged in either an ascending or a descending configuration, depending on their baseline perception. The results showed that the meaningful prime shifted participants’ perception of the tritone paradox in the direction indicated by the musical notation. This effect was stronger for musicians than non-musicians. Experiment 2 replicated Experiment 1 and further ascertained that this effect occurred unconsciously and was not due to regression to the mean. Together, the results of this study demonstrate that relevant visual images can unconsciously influence auditory perception under conditions of ambiguity.