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

120 CHAPTER 8. SOFTWARE IMPLEMENTATION
• graphical display of the modelled instrument
• dimensional representation of the instrument familiar to a maker and not too unlike conventional
descriptions
• instrument files that could be saved (to form part of a maker’s compendium or ‘toolbox’
of designs)
• graphical display of tuning data (most important) and playability and timbral data (less
important but still desirable)
• display of pressure and flow profiles along the instrument, to aid placement of e.g. register
holes and to inform the maker’s intuition
• simple, intuitive layout.
The remainder of this chapter describes the layout and design of the user interface. The Java
code has not been included in this thesis since the software may be made commercially available
and the owners of the intellectual property do not wish the complete source code to be
published at this stage. The reader is invited to contact the author for up-to-date information.
8.2.2 Brief description of application features
A screen shot of a window in the user interface ‘FluteCAD’ is shown in Figure 8.3. The ‘Design’
tab of the window is active and the body joint of a modern flute is displayed. The window contains
a schematic diagram of the instrument (top) and a panel of dimensions (bottom left). A
user navigates between the different instrument components using labelled tabs. Length dimensions
are in millimetres and measured from either the centre of the embouchure hole (for
the head joint) or from the upstream end of the bore (for body joints). Holes are described
by their diameter, length and angular position on the flute body (relative to that of the embouchure
hole). If a hole has a key, the dimensions of the key are likewise entered. The bore
of each instrument joint is described by two or more points joined by straight lines. The application
uses a detailed set of validation rules to ensure that any changes made to the flute
design do not result in an invalid instrument. (An invalid instrument may have e.g. holes too
big to fit within the bore.) Any invalid requests are rejected by the application and a message is
communicated to the user via an error message bar at the bottom of the window.
The ‘Fingering Chart’ tab of ‘FluteCAD’ is shown in Figure 8.4. For each note the fingering
is an array of booleans, with a closed hole represented by a true and an open hole by a false
literal. When the ‘Tuning’ tab of the user interface is selected, the application calculates the
impedance spectra for all fingerings (using ‘PlayedImpedance’) and analyses these spectra for
playable notes (using ‘AnalyseNotes’). The tuning results are displayed both graphically and in
tabular form (Figure 8.5). Each octave is displayed as a separate series, so that notes with the
same or similar fingerings (e.g. G4 and G5) can be easily compared. Analogous graphs of the
playability and strength of each note are given on separate tabs.
The final tab gives detailed information about a single (selectable) note. In Figure 8.6 the
note display tab for the note D7 is shown. The pressure and flow profile for the note is given,