Orfeo

6. Stresses & structures in design [100-137]

It is argued that the most fundamental test of a musical instrument's
design it not how well it meets its musical demands - how it is
judged to play or sound - but whether it can play or sound at all. In
stringed instruments this means especially an ability to withstand
the powerful compressions, tensions, torsion and shear forces
generated by the tensioning of the strings. The complexity of these
forces places stringed instruments amongst the most complicated
and fascinating of all products of ancient technologies. As
instruments evolve the musical requirements they serve can only be
realised after structural integrity has been achieved; yet this may
conflict not only with practical and acoustical needs of performance
but also with the wider modus operandi of performers. This chapter
seeks to identify in the material record evidence of the engineering
strategies which have been developed to maximise structural
strength and mitigate weakness. It argues that, like high levels of
investment in manufacture, evidence of special structural adaptation
contributes to our understanding of the changes in musical and other
behaviour which demanded them.

Analysis of stresses acting on generalised structures offers a first
step, revealing the structural differences between harps, lutes and
lyres. Through time distinct structural adaptations appear in
resonator-shells, sound-boards, superstructural beams and joints,
and in the micro-engineering of bridges, especially those made of
fragile materials like amber. In beams curvature is frequent, as in the
ancient Greek tortoise-shell lyre where it may protect the joints from
jack-knifing. Elsewhere beams adopt T and Delta-shaped
cross-sections, maximising their strength-weight ratios. Wood grain
is frequently oriented to structural advantage. No evidence is found of
any underlying structural theory but finds reveal much shared
empirical knowledge. A particular high point in musical engineering
is the early medieval lyre - yet it also suffers from structural
weaknesses which in experiment can lead to unwanted flexion and
even catastrophic failure. Such failure is evidenced in the
archaeological record in the splitting of sound-boards and snapping
of tenons. Repairs and reinforcements reveal further detail. But some
structural myths are also exposed. Metal 'strengthening' plates on
the joints of Anglo-Saxon lyres are incorrectly placed to brace
against string tension, so must have served some other purpose.
Doubt is cast on putative forward-leaning superstructures of lyres
shown in ancient Greek and Roman art (Maas 1974), suggesting
these and other structurally inefficient types to be simply errors in
depiction.

Structural adaptation is invoked to explain differences between the
strong-jointed cantilever structures of ancient Eastern angle-harps
and the weaker-jointed, more symmetrical frames of their later
Western triangular derivatives, showing their new structural forepillars
to be one of a number of indications of adjustment to indigenous
structural practice.

7. Practical & musical elements in design [138-165]

Elimination of decorative and engineering dimensions permits for the
first time a clear view of the musical needs driving these design
traditions. Acoustics properties investigated by experiment include
consideration of the efficacy of sound-holes in harps and later bowed
instruments and their apparent absence from earlier lyres. Handling
and management characteristics are also considered, particularly
those related to variation in size, weight and smoothness of outline.

The elegant smoothness of early medieval lyres of the 7th and 8th
centuries is shown to render them unusually portable and may
reflect the itinerancy attributed to poets in Old English texts. A
need for increased efficiency in tuning may have driven the change
from archaic external tuning-levers to modern tuning-pegs, a move
which had already begun by Roman times, apparently involving use
of socketed tuning keys from the outset.

General performance characteristics evaluated include numbers of
strings, whether they are arrayed symmetrically or not, and how
they might have been tuned. The symmetry of Classical and early
medieval lyres supports narrow intervals, and a scalar tuning is
proposed for most lyres (and harps, but not necessarily lutes) up
until the advent of bowing. This is consistent with a diatonic
system reported by Hucbald of St-Amand in the 9th century.
Images naturally show the orientation of harp tuning, but the
orientation of lyre tunings has not previously been established.
Evidence is adduced to argue that here too the bass string was
furthest from the player.

It is observed that while many early string traditions exhibit both
plucking and strumming techniques the latter are especially
encouraged by the smallness of surviving medieval lyre bridges.
Plectra are routinely shown in images of ancient Greek lyres, but
although reported in some early medieval texts they are not
convincingly evidenced in either finds or pictures. Use of harmonics
is encouraged in lyres and harps by extensive left-hand access to
both sides of the strings. In Greek images of lyres and early
medieval lyre finds provision of wrist-straps shows that both hands
were intended to be used. The technical opportunities offered by
the introduction of bowing (Bachmann 1964, 1969) are considered.

Functional differentiation of the player's left and right hand is
considered, observed similarities being used to argue that Western
and Eastern lyre traditions (and indeed later Western bowed lyres)
are organically connected - however distantly. East-West
differences in harp-playing, however, reveal a musical discontinuity.
Not only is the instrument played upside-down but images show
players adopting distinctly lyre-like hand gestures - confirmed by
wear patterns on extant Gaelic harps.