2013 Annual Meeting of the California-Nevada Section of the APS
Volume 58, Number 14
Friday–Saturday, November 1–2, 2013;
Rohnert Park, California
Session F1: Plenary Session II
9:00 AM–10:30 AM,
Saturday, November 2, 2013
Ives
Room: 101
Chair: Lynn Cominsky, Sonoma State University
Abstract ID: BAPS.2013.CAL.F1.2
Abstract: F1.00002 : Physics of Baroque Bassoons
9:45 AM–10:30 AM
Preview Abstract
Abstract
Author:
Bryant Hichwa
(Sonoma State University)
Baroque bassoons differ markedly from the modern instrument. Since the
Baroque instrument has only 4 keys, the remainder of tone holes must be
within a hand's reach. The holes must be obliquely drilled into the conical
bore, making the acoustics both interesting and challenging. Additionally,
museum directors are quite reluctant to allow researchers access to these
300-year-old instruments.
To acoustically characterize Baroque bassoons a non-linear least squares
procedure and precision measurement techniques of physical dimensions were
developed. The current study involves 93 original 18$^{\mathrm{th}}$ to
early 19$^{\mathrm{th}}$ Century Baroque Bassoons and 17 reproductions.
Tone hole positions ``determine pitch'' is a characteristic unique to
woodwinds. This allows an exhaustive study comparing 47 temperaments
selected from English, French, German and Italian temperaments. Including
forked fingerings, E-flat and B-flat, enhances sensitivity. Results indicate
5-7 preferred temperaments for each bassoon. For seven of the makers, a
study of multiple original instruments allows a unique temperament
determination.
The model demonstrates the proficiency of 18$^{\mathrm{th}}$ century bassoon
makers. It is also predictive. In about 25{\%} of the instruments, minor
changes to the wing joint dimensions result in a significantly improved
``designer'' bassoon. The model illustrates bassoon evolution leading to
changes in mid-19$^{\mathrm{th}}$ century bassoons.
The bassoonist's embouchure modifies the double reed volume, which in turn
changes conical bore volume, which alters playing pitch and higher
harmonics. Since the acoustic model predicts only the 1$^{\mathrm{st}}$
harmonic, an impedance calculation using measurements of the conical bore
and tone hole positions and shapes was under taken. This independently
yields the playing pitch, harmonics, reed volume and temperament.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2013.CAL.F1.2