The audibly different sound of the Steinway and Stuart of the note C2 65.406 Hz can be understood initially by looking at the strings of both instruments. The Stuart piano uses 2 wound strings, a bichord, wound in stainless steel nickel-plated¹³⁰ , and the Steinway uses 3 wound strings, a trichord, wound in copper. The Steinway piano uses Roslau piano wire, made in Hamburg, which are wound in non-tinned copper¹³¹ . Roslau piano wire is the music wire of choice of many piano manufacturers of concert grand pianos. The Stuart strings are manufactured in France, by Stephen Paulello, who implements slower drawing methods of steel string production, and new composite alloy mixtures in the steel, to achieve steel of a higher tensile strength. Paulello’s innovations have enabled Wayne Stuart to extend the frequency range of the piano compass.

Samuel Wolfenden writes about the excess weight of the copper wound string,

Naturally, such excess [of copper winding weight] whether partial or total, tends to aggravate the characteristic defect of bass piano tone, viz., the preponderance of the first over-tone, often so pronounced as to eclipse the pitch of the fundamental, particularly when the strings are very short. ¹³²

In response to this problem, Wayne Stuart implemented changes to the standard piano design:

1. Extended the piano scale of the long bridge, lower by two notes,
2. Bichord of Paulello ‘M’ steel wire, stainless steel wound of greater thickness ,length, and tensile strength with increased applied tension.

Pianos have to be designed around these limitations and most of the issues in traditional designs stem from music wire limitations. The 7 trichord bass string groupings of the model D Steinway is a classic example of music wire limitations.¹³³

The problem with thin wound strings is that they are unstable and often sound rather poor. In this region[tenor strings]the very thin core and covering combinations are also weak in sound and Steinway uses three instead of two. Wound strings are harmonically incompatible , ….. two are bearable, but three are often noisy and unbearable… a very poor compromise.¹³⁴

The contrasting dimensions of the Paullelo and Roslau piano wires are illustrated in table 4.24a in the 4.2a appendix. The diameter of the Paulello/Stuart core wire is .125mm thicker than the Steinway/Roslau wire, the Paulello/Stuart cover wire is .47mm thicker and of Stainless Steel, whereas the Steinway/Roslau strings are wrapped in copper. Stainless steel is 1.9g per cubic cm lighter than copper in specific gravity¹³⁵ . The tensile strength of the Paulello/Stuart wire is 481 N/mm² higher than the Steinway/Roslau. The Paulello/Stuart strings are 235mm longer, and are set at 65.3kg higher

^{130     8} Paulello, (accessed 21st February 2014).
¹³¹http://www.fortepiano.com/wire/RoslauPiano/roslaupiano.htm (accessed 21st February 2014).
^{132     2}Wolfenden, Art of Pianofarte Construction,209.
¹³³Wayne Stuart, email interview with author, 23 Nov 2012
¹³⁴Wayne Stuart, email interview with author, 5th March 2014
¹³⁵Specific Gravity Of Metals Table , (blog) CSGnetwork, http://www.csgnetwork.com/specificgravmettable.html (accessed July 2014).