Flute acoustics: measurement, modelling and design - School of ...

10
Chapter II
Theory and literature review
This chapter gives a brief overview of the theory and an introduction to the literature relevant
to this project. Firstly, the history of flutes and flute making is covered, and some ideas are
offered as to where flute design may be headed. The theory of woodwind acoustics is then
reviewed, and equations are presented where appropriate. Finally, several woodwind models
reported in the literature are discussed and compared with regards to the expected outcomes
of this project.
2.1 FLUTES AND FLUTE MAKING
Modern instruments in the extensive flute family include the modern orchestral transverse
flute, the baroque transverse flute, the recorder, flue organ pipes and the Japanese shakuhachi
(Baines 1967). Sound is produced in these instruments when a stream of air interacts with a resonating
body. This section briefly reviews the history of flutes and flute making, with particular
reference to the transverse flute from the baroque period onwards.
2.1.1 History
Flutes are the oldest known musical instruments and have been made at least since Palaeolithic
times (Dauvois et al. 1998). The earliest flutes were made of bone. Most of these early flutes
were close to cylindrical, with up to six finger holes. Figure 2.1 shows a picture of an early bone
flute, along with a baroque flute, a classical flute and a modern flute.
The baroque flute was developed in the second half of the 17th century (Bate 1975), and
included two important innovations—the bore was made conical rather than cylindrical (with
the largest diameter in the section near the embouchure hole) and a single key was added. The
conical bore improved the intonation, and the key made the flute fully chromatic. As a result of
these changes, the flute gained in popularity, particularly as a solo instrument. On a baroque
instrument the notes in the diatonic scale are produced with simple fingerings (consisting of
an array of closed tone holes followed by an array of open tone holes) and most other notes are
made with cross fingerings or the use of the key. Consequently, considerable variation exists in
the timbre, volume and ease of playing across the chromatic scale.
The flute continued to develop through the classical period, as more keys were added and
the holes were enlarged. Makers at this time generally sought more volume, a ‘stronger tone’
and greater uniformity of timbre among different notes. On a classical flute, fewer cross fingerings
are used, and are necessary only in the third octave of the instrument.
Most flutes of the baroque and classical periods play a natural major scale based on the
note D4. Some classical flutes have keys for the notes C4 and C♯4, and some are designed to
play in different keys (such as B♭ or E). The piccolo is a small flute that generally plays an octave