Peirce's rhematic iconic qualisign challenges the community of Peirce scholars in mainly three ways: First, ontologically, it merely exists as a pure possibility. Second, epistemologically, it is never perceived as itself, but it must always be embodied in a sinsign. Third, it seems impossible for a researcher to communicate a scientific research about it. This paper tries to overcome these difficulties by suggesting a possible case of the rhematic iconic qualisign; the humming sound of pianist Glenn Gould. Peirce's definition of the First in its relation to feeling and consciousness is provided as the theoretical ground of this case study. The dominance of the First in Gould's humming sound gives rise to a conclusion that music's essence is its firstness, namely the quality of feeling.