Kasha Publications List

Compiled by Gila Eban

1. ) * Guitar Design Papers by Michael Kasha *

Scientific Development of a New Classical Guitar: Author, Tallahassee,
Florida, 1971.

Physics and the Perfect Sound: Britannica Yearbook of Science and the Future,
1974.
(A longer version of the article has been circulating in various revisions,
titled: Model Physics and the Optimization of the Modern String Instrument.)

Symmetry and Nodal Properties: Tokyo Science University Lectures, 1979.
(There's a slightly revised later version, in which statement/s about
the bridge's rocking motion is/are deleted)

Applied Mechanics and the Modern String Instrument -- Classical Guitar
(with Nicholas Kasha), Journal of Guitar Acoustics #6, Sept. 1982. (Seven
J.G.A volumes recently re-issued in one volume).

Kasha Model, Builder's Manual, Guitar Edition, 1972, Tallahassee, Florida.
(Hard to find, but worth it partly because of
drawings that show the early evolution of the soundboard and bridge. Some
design features still used today by most Kasha guitar builders).

U.S Patents by Michael Kasha: (Patents expire after 17 years)

Guitar Construction, U.S Patent 3,443,465, May 1969 (Filed Dec.1966).
(Fascinating in spite of being written in legalese).

Bridge for Stringed Musical Instrument, U.S patent 4,016,793, April 1977
(Filed May 1975).

Bracing Structure for Stringed Musical Instruments, U.S Patent 4,079,654,
March 1978 (Filed May 1975).

Bass Bar and Coordinate Bridge for Violin Family, U.S Patent 3,494,239
(I do not have a copy of this one but assume the number listed here is
correct)

 

2.) * Background reading on Kasha Guitar Design *
by Michael Kasha

A New Look at the History of the Classic Guitar: Guitar Review #30, (1968)
pages 2-12.

From Musical Aesthetics to Psychoacoustics to Physical Mechanics in String
Instrument Design: Conference on the Biology of Music Making, Denver,
(Colorado), 1984, pages 205-207 Ed. by F.L Roehmann and F.R Wilson, MMB
Music, St. Louis. (The copy I have may be a later version -- one of the references
listed is dated 1987). The paper mentions an elusive "silkiness of tone,"
which may or may not be "inherent in the structure of the instrument." The
question of what is inherent in an instrument's structure and what is
introduced by the player is central to any discussion of old vis-a-vis. new
guitar designs.

The Relation of Science to Aesthetics in Lutherie: American Lutherie #8
(1986) pages 36-37.

Quadratic Equations Tune Guitar's Vibrations: Larson Texts, 1995.

If I'm not mistaken, Larson Texts is now part of larger publishing company,
so this article may turn up in some algebra or college
textbooks, but I do not know any specifics.

The paper is worth reading because the math in it is fun, and, being such a
simplification of the real world soundboard, is easier to investigate in
detail. It deals with the relation between plate-diameter and its
fundamental-mode frequency, so the "quadratic" part soon turns into studying
the function defined by

y = 1 over {square root of x}

But once you start reading the paper for what it does _not_ address, you can
see
how large the gap between theory and practice is, and how many
different ways there must be of bridging it.

 

3.) * Kasha Design Guitar Construction articles by yours sincerely (Gila
Eban) *

Kasha Guitar Soundboard: GAL Data Sheet #243 (1983). Ten pages. Out of
print but the full size instrument plan should still be available. It's a
bit outdated but the basic ideas and approach still stand. More information
is available on this website.

Kasha Soundboard Without Waist Bar: American Lutherie #8 (1986) pages
8-14. A "muscle-project" of sorts, which turned out some interesting
scientific data.

Variations on an Asymmetric Bridge: Author, 1994 Riverside CT.
(revised 1996) Covers several different topics. Local modes need boundaries
in order to be "local," but can a local mode be too provincial? Read Part
III.
Would you glue a long bass bar on the "treble plate?" See Part V.

 

Quadratic Equations -- The Series: Author, 1997-99 Riverside CT.
Not only is there a "gap between theory and practice" as mentioned earlier,
there's a gap between theory and itself! Five "exciting episodes" (besides
Kasha's original) have been written and circulated among a small group of
"fans," and 1 or 2 more may be written soon. The math if fun, but the
"presentation" rather, ...er..., unconventional. <G> For example, one of the
"episodes" is titled "Quadratic Equations Search for Self Realization," and
the one now in progress is titled "Addition and Multiplication Go to War."
You get the idea. :-)

 

The Relation of Musical Acoustics Research to Guitar Design and Building:
Proceedings of the International Symposium on Musical acoustics, 1998 (ISMA
'98) pages 97-102.

This conference was co-sponsored by the Acoustical Society of America (A.S.A)
and the Catgut Acoustical Society ( www.marymt.edu/~cas/ ). The whole
Procdeedings volume is very much worth reading. It contains
about 70 papers on a wide variety of musical instruments, plus a section on
Perception and Psychoacoustics, total about 390 pages. Copies can be
obtained from the A.S.A office (500 Sunnyside Blvd.,
Woodbury, N.Y 11797, email <asa@aip.org>) but I have no idea how many were
printed and are still available.

The paper contains drawings and information about the "Rochester 1" Kasha
model, said information is, I believe, highly "usable" by luthiers.

LOCAL MODES OR MULTI-NODES? BOUNDARY-CONDITIONS OR INITIAL CONDITIONS? SOME THOUGHTS ON ASYMMETRICAL GUITAR SOUNDBOARDS, by Gila Eban, 1999. Published on this website in the "Articles" section.

Normal modes of a radically braced guitar determined by electronic TV holography, by Thomas D Rossing and Gila Eban. Published in The Journal of the Acoustical Society of America, Vol. 106, No. 5, November 1999

4.) * More Kasha design info on the Net *

 

Past postings in rmmb and other newsgroups: http://www.deja.com (the site
has its own search-menu, "power search" may be the best. Pick keywords
including "Kasha" and "guitar"). Some "polemic" but many "technical" items.

 

Soundboard Drawings: Ray's website also has 2 of my soundboard drawings,
similar to those in the ISMA 98 paper. You can get the full-scale versions
from me, or print from the website and take the result to Kinko's (or Office Max?)
to enlarge to full size (body length 48.9 centimeter, lower-bout width 36.2
cm). This kind of photocopying introduces distortions, so don't expect
the enlargement to exactly match all these dimensions. However, the point
isn't to copy a drawing precisely as much as to use the ideas in the articles to
create your own soundboard bracing pattern/s, appropriately matched to the
body-template, string-scale, woods, etc., that you choose, and the tone you
want to get. Bar widths and heights are not specified, but they fall within
"traditional" parameters for classical guitar soundboards.

 

Some of the items listed above are out of print hence difficult to obtain.
Email me at Geguitars@aol.com or write to me if you want help with that.

Gila Eban
P.O.Box 95
Riverside, CT 06878
U.S.A.