[ An article by Toshihiro Hamamura of Japanese International Chapter,
 [ MBSI, published on page 30 of the MBSI journal, "Mechanical Music"
 [ for July/August 2015, says "Tomoko Nakaya reported on her study of
 [ the differences in tone caused by the materials used to make disks,
 [ which is one of our chapter's projects."  -- Robbie

Most of us know that when a note is plucked on a comb with a note next
to it tuned to the same frequency, the plucked tooth will vibrate in
sympathy with the original tooth.  Many times on the bass notes of a
comb you can see this effect fairly easily.

In the same way, a vibrating tooth below a moving disc can, to a minor
degree, get the disc to vibrate.   This could enhance the sound of the
music.

If we consider the copper discs made by Porter and the steel and or
zinc discs made by other manufacturers, one can imagine the copper
being able to pick up vibrations better than the zinc, which would be
a soft material, and the steel which would be stiffer material.  This
could be confirmed by having the same tune played with different
materials for the disc.

Tony Ciuffini - The Musical Box Doctor
San Pedro, California
http://www.musicalspecialties.com/ 
msi@dslextreme.com.geentroep [delete ".geentroep" to reply]