Several years ago, my husband called me into his studio as he was practicing for an upcoming solo violin concerto performance with the National Symphony. As I entered the room, I noticed three bows lying on the floor. Without a word, he motioned for me to be seated on the sofa. He picked up the first bow and began to play a passage of the music. He set this bow on the floor, picked up the second, and played the same passage. He repeated this process with the last bow. When he finished, he paused and looked at me. I motioned to the middle bow. He nodded in agreement. This was the bow he would use for the performance. Musicians communicate through sound. The wordless exchange of musical ideas described here exemplifies the fine-tuned discrimination of sound that is at the heart of music aptitude. While listening to the repeated musical passage, my husband and I were both aware of the subtle qualities of sound that each bow produced as it was drawn across the strings of the violin. The first had a gutsy, robust sound; the second a melancholy, sweet quality; the third a square cleanliness. We listened, interpretively reflected on these qualities, and decided that melancholy sweetness would best match the mood of the Armenian folk tunes within the solo concerto. Words were not necessary. Obviously, this level of musical communication is quite sophisticated. It relies on years of musical training, listening, and interpretive understanding. However, if you layer away the training and skills, we arrive at the underlying discrimination of differences in sound. The discrimination of sound, prior to any formal training, is where music aptitude begins. Music exists through sound. Sound develops into music through combinations of rhythm, loudness, pitch, and the different qualities of these sounds. Music psychologists define the capacity to sense these musical components as music aptitude. The more discriminately one senses subtle differences in these components, the higher one’s music aptitude. Music aptitude combines inherent musical capacities with listening skills that may develop without formal training or education.