Auto Music Composer Light makes a music that is very comfortable. General songs consist of melody, chord and rhythm. And these three elements influence each other. But a tone of a musical instrument is not related to these. However, we made the new music theory which connects a "tone" with a melody, a chord, and a rhythm. "Auto Music Composer Light" decomposes the tone of a musical instrument, and re-compounds it in the process which makes music. We succeeded in making new music by compounding sound. "Auto Music Composer Light" makes infinite number of music.