To many people, music is a mystery. It is uniquely human, because no other species produces elaborate, well organized sound for no particular reason. It has been part of every known civilization on earth. It has become a very part of man's need to impose his will upon the universe, to bring order out of chaos and to endow his moments of highest awareness with enduring form and substance. It is a form of art dealing with the organization of tones into patterns. Despite of cultural differences, music from different civilizations seems to consist of some building blocks that are universal: melody, harmony, rhythm, etc. Almost all musical systems are based on scales spanning an octave---the note that sounds the same as the one you started off with, but at a higher or lower pitch. It was discovered by Pythagoras, a Greek philosopher who lived around 500 BC, that the note an octave higher than another has a frequency twice high. The notes that sound harmonious together have simple rational number ratios between their frequencies. It is those implicit structures and relationships in apparently mysterious musical experience that I am interested in exploring here. As a scientist by training with a consistent passion for classical guitar playing, I would like make an attempt to explain the musical experience in terms of science and mathematics, hoping to fill some gaps between the knowledge of scientists and artistic intuition of musicians.