The Fibonacci, designed by Frank Pollaro is hand built from natural Macassar ebony and takes its name from the famous spiral that denotes nature's geometric principles.

The Fibonacci spiral is detailed on the Model D nine foot concert grand piano's lid in veneer form, and its lines also denote the instrument's footprint; its body following the spiral's outward curve.

"Designing Steinway & Sons' 600,000th piano was an honor and a challenge," said Pollaro. "To me, knowing that this piano would become part of history meant that it had to be more than just a beautiful design, but also needed to visually convey a deeper message."

The Fibonacci took 6000 hours over four years to complete and now that it is finished, it will be showcased at a number of special events in the US and beyond over the summer before being offered for sale for US$2.4 million.