The clean lines of early L-5s, D'Angelico's and D'Aquisto's are what made me want to start building archtop guitars. These instruments had a certain something that, to my eye, made them timeless and "classic" in the same way that the refined profile of golden age Italian violins are timeless and classic. The visual appeal of those instruments seemed to be a result of their proportions and dimensions, both in their overall shape, and also with the way the individual components related to each other.

Inspired, in 1995 I began building fairly traditional 17 inch guitars but was never fully satisfied with the body shape, so the quest to design my own body shape began. I made many attempts but each new guitar sent me back to the drawing board. Years passed and I still was not completely happy with the aesthetics of my guitars.

In 2003, while still trying to find that elusive body shape I cut out pictures of my favorite guitars, measured them and using math, scaled them up and found their actual dimensions and I started looking for any and all common factors.

After two fruitless and frustrating weeks of drawing and re-drawing body shapes I still was dissatified with them. There was something missing but I was determined to find those dimensions and proportions that were so appealing to me.

I happened to be listening to The DaVinci Code audio book one day while I was drawing, and the Harvard professor who is the main character in the book started giving a lecture about Phi or the Divine Proportion. As he was speaking, things started to click for me, and at the end of the lecture, when he mentioned Stradivarius and using Phi for his f-hole placement, the last missing piece fell into place.

Simply put, Phi is a ratio of 1 to 1.618. It is sometimes called the Golden Mean or Golden Section, as well as the Divine Proportion. It is derived from the Fibonacci sequence, which is 1+1=2, 1+2=3, 2+3=5, 3+5=8, 5+8=13, 8+13=21 and so on. If you take any of those numbers and divide it by the number immediately preceding it, you will come up with an approximation of 1.618. The Divine Proportion is found everywhere in the universe and throughout nature, in the spiral of the milky way, the double helix of DNA, nautilus shells, pinecones and in our bodies. Phi is a basic building block that is found in art, music and architecture.

Once I learned about Phi I realized that many of those classic guitars had proportions, dimensions and relationships that approximated the Divine Proportion. Whether this was intended or merely intuitive I do not know but I decided to consciously apply Phi in my designs.

I found many opportunities to implement the Divine Proportion in my new Phidelity body shape. While I do not use Phi as a strict formula, I have found that it is a great starting point, and I believe utilizing Phi helps me create instruments that are both visually and aurally harmonious.

If you are interested in learning more about Phi, there is a great website Golden Number that goes in to it in depth. You may want to check it out!