Bell worth listening to
Barbara Hall 10 November 2000
A composer and a sculptor from Melbourne have developed the world's
first harmonic bells. By the end of 2001, there will be 2069 of
Casting the first harmonic Federation
bell in Castlemaine, central Victoria. Photo by Barbara Hall.
3D computer graphics show the adjustments
to the basic bell shape. Image provided by Neil McLachlan .
Ross Edwards (left) and Neil McLachlan at
the Castlemaine launch of the project. Photo by Barbara Hall.
Examining the prototypes
When composer Dr Neil McLachlan decided it had to be possible to
cast a true harmonic bell, the three years' research that engrossed
him and sculptor Anton Hassell produced many significant outcomes
that involved other intellectual explorers along the way and will
soon give delight to a lot of people.
In May 2001, the most public result of their research
will become the Field of Bells, a permanent public art work installed
in Melbourne, timed to celebrate Australia's Federation centenary.
In the Melbourne Town Hall, the federation festival
will feature a new Australian symphony using eleven of the twenty-five
McLachlan and Hassell harmonic bells which are being given by the
Victorian Government to the Melbourne Symphony Orchestra.
A third outcome will be 2001 tuned handbells housed
in the new Melbourne Museum, and available on loan to communities
A lasting, world-wide legacy is that, for the first
time, bells truly can be counted as musical instruments with timbral
characteristics that composers can include in all orchestral scoring.
Neil McLachlan, who has a PhD in physical chemistry,
is a research associate and adjunct professor in RMIT University's
School of Architecture and Design where he is developing new courses
and an acoustics design studio.
Anton Hassell, co-director with Neil of the Australian
Bell Company, is casting many of the smaller bells at his art foundry
at Mia Mia. He is completing his PhD in public art for architecture
and design at RMIT University, where he shares a research office
with Neil in the Faculty of the Constructed Environment.
The dream three years ago to create the world's first
harmonic or tuned bells flew in the face of widespread scientific
negativity. McLachlan and Hassell were prepared for the long haul,
and the fact that, as Neil said, "many great discoveries are at
the edges of known disciplines." So they were not surprised that
the project required them to forge collaborations with musicians,
acoustic engineers, computer engineers, aerospace engineers, universities-principally
the nurture of research within the Faculty of the Constructed Environment-and
a foundry at Castlemaine run by the Billman family. There were also
hundreds of hours of refined computer modelling, and struggles with
finance because of the great divide in the funding of science and
In August 2000 Ross Edwards, the Sydney composer
whose third symphony will use 11 of the new two-octave bells with
the Melbourne Symphony Orchestra next year, watched the dramatic
pour of 1800 degree Celsius molten bronze to make a 2 tonne bell
for the Field of Bells. He said he would be pleased to see the end
of tubular bells in the orchestral line-up.
"I hope they go. Most composers can't bear them.
The new bells bring in a whole new set of sounds to composing,"
Neil McLachlan said "it will create many new opportunities
in music performance and composing. A bell that can match the harmonic
sequence of the human voice has true pitch, a very pleasing sound."
Until these determined Australians, western bells
have not really been instruments in the orchestral sense. Carillon
bells, not used in a musical setting, don't require tuning.
"The engineering design process will apply to all
percussion instruments, xylophones and gongs and bells. With funding
now at this point we could make bells with any ratio of frequency.
We have also designed various polytonic bells, individual bells
with two or three pitches," Neil said.
It has taken almost three years. At the August launch
and pouring, Neil and Anton proudly introduced the harmonic overtones
and soft melodic tones of some of their bells to an audience which
included the State Minister for the Arts and Minister Responsible
for the Centenary of Federation, Hon. Mary Delahunty.
Stringed instruments, which vibrate in one dimension,
have a harmonic sound. Three dimensional vibrations could not be
tuned harmonically until now.
"The sound of a bell is a series of frequencies called
partials. When these partials fall into a certain series, they are
called a harmonic sequence. Harmonic sequences are the basis for
the human voice and most musical instruments. They're what we use
to determine pitch. This will open up a whole lot of new possibilities
for bells to be truly integrated into new compositions: for the
first time, they can be actually scored for," said Neil McLachlan.
In the seventeenth century, bell makers started tuning
their handiwork in the hope of achieving a harmonic bell. By the
end of the nineteenth century, they had worked their way up to five
partials but, Dr McLachlan says, "one extra partial frequency was
added to the harmonic series. It was tuned to a minor third interval
and creates the ambiguity of pitch heard in these bells. Most nineteenth-century
bells are pretty out of tune."
Very little happened until the 1980s when engineers
in a Dutch bell foundry started using computerised finite element
analysis, creating three-dimensional models to predict an object's
mechanical properties. Using this method, the Dutch tuned the individual
partials-moving the minor third to a major third interval-which
improved the sound but was not a true harmonic bell.
It seemed impossible to create a true harmonic bell
using the classic European bell shape, so McLachlan and Hassell
walked away from the European bell shape. They wanted to keep their
options as wide open as possible and start trying some radical strategies.
"The only rules were that it be semi-enclosed and
made of bronze," McLachlan said. Then they came across some powerful
software and hardware. McLachlan found that a soon-to-retire RMIT
mechanical engineering colleague, Dr Josef Tomas, had in his company,
Advea Engineering, developed software called ReSHAPE to analyse
and fine-tune 3D models of car parts to control vibration and reduce
noise. McLachlan realised this was just what they needed to study,
predict and alter individual partials of bells.
Josef Tomas was delighted. His software had been
used by the big names in the industry: Volkswagen, Ford, General
"It's so much more poetic than air bags and car crashing.
Of course, we had to change the program. We'd only ever tried to
get rid of noise, never make it," he said.
Using computer music software, McLachlan would create
a bell and run it through another program to hear how it would sound.
He then asked ReSHAPE to help by computing optimal design solutions
by configuring the 3D model to a specific individual partial while
leaving other, already tuned, partials unscathed. Computers were
used to model not only the ways bells will vibrate but how people
From this point, new manufacturing technologies enable
the designs to be produced with high precision. Inside and outside
shapes produced with laser cutting technologies are turned in resin-coated
sand, and these segments are then assembled to complete the mould.
"We are looking forward to having them in the field
where people can walk among them. In bell shaping, the object brings
our art forms together. This musical instrument is a also public
sculpture," said Anton Hassell.
The prototype is a conical bell with seven harmonically
tuned partials. Although there are additional partials in a harmonic
sequence, this is a true harmonic bell because these other partials
cannot be heard by the human ear.
In traditional bell tuning, foundries cast a bell
and bore it out until the makers find a sound they like. The more
exacting techniques developed by McLachlan and Hassell involve hundreds
of hours of number-crunching on the SX-4 computer for each bell
design. The program can control the timbre and indicates the correct
three-dimensional form-the only way to model improvements.
Neil McLachlan was writing music for the Melbourne-based
Danceworks company in 1989, then formed his own company, Gonghouse,
when he began wrestling with how to tune bells.
"We set out to make musical works for gamelan and
classical Indian bells and percussion. I also did a lot of work
at Lake Tyers, with the Aboriginal community, developing performances
using their own stories and instruments," he said.
Righting the acoustic wrongs embedded in the hierarchical
history of western music was behind the work Neil did with a Yongu
musician from the Northern Territory, finding a way to tune the
guitar to the didgeridoo instead of the reverse. The solution involved
replacing all the frets. Neil also worked extensively in the Philippines,
helping build instruments for indigenous people to dance to, as
part of their evidence for land rights claims.
"I don't use western timing, I use just tuning. Music
was commodified after the industrial revolution because of the demands
of mass production. There was a break with tradition. For the first
time, instruments and their tuning had to be standardised, because
scores were being written down for the first time," said Neil.
The explorations of non-conformist American composer
Harry Partch became a model for Neil. "Consonance is about the need
to control the timbre," Partch wrote.
Neil was intrigued but not convinced by an article
written in the mid-eighties by Dr Andre Lear, the eminent Dutch
musicologist and bell expert, claiming that a pitched bell was an
impossibility. Trawling the literature of several disciplines, MacLachlan
came across Neville Fletcher at the Australian National University
who was working along the same finite element analysis path as the
Dutch engineers and had co-written with Thomas Rossing what McLachlan
considers the bible of instrumentology, a book called 'The Physics
of Musical Instruments'. But they too believed there could be no
"In 1998 in Japan, China and Korea I photographed
temple bells and recorded their sounds. Some date back to the sixth
century. I entered their sounds on my PC to measure the frequencies
of their partials, or the different notes within each ring; as well
as the partials of many bells of Europe. This was the way we started
designing bells whose partials would all sound harmonious when played
together: Perfect partials equal perfect harmony," said Neil McLachlan.
The computing meant Dr McLachlan could 'ring' a bell
without that bell ever having been cast. "It's a lot easier to redesign
a bell on a PC screen than it is to change it when it's 25 kg of
bronze," he said.
Support worth $2 million for the harmonic bells project
has come from Arts Victoria and the Melbourne International Festival
for the Arts. There has also been intellectual and in-kind support
from Elizabeth Lindqvist, the head of the acoustics laboratory in
RMIT University's Faculty of Applied Science. Josef Tomas linked
McLachlan with bright research students, notably Behzad K. Nijieh,
who was educated in rocketry in Russia and is doing his RMIT aerospace
engineering doctorate on a space debris collection mechanism.
Behzad and Neil recently co-authored an article in
a mathematical magazine on the vibrational behaviours of cylindrical
forms. Neil has posited the concept of a museum of sound in 'Museum'
magazine and published work on acoustics in 'Architecture Australia'.
His article on notated rhythm in cyclic form was published in the
'Leonardo' music journal.
Neil McLachlan's most recent installation work was
a set of gongs for Sydney's new Olympic Park.
For the Field of Bells, in the new Riverside Park
being built by the City of Melbourne, the largest of the forty-three
free-standing, electronically controlled bells weighs 3 tonnes and
stands almost 2 metres high. In many shapes, timbres and tunings,
the bells will chime regularly during the day, play specially composed
soundtracks and be a feature of performances in the park over many