Music Representation of Score, Sound, MIDI, Structure and Metadata All Integrated in a Single Multilayer Environment Based on XML - Intelligent Music Information Systems: Tools and Methodologies - page 316

Figure 6. The measure encoded in MX format

<measurenumber="1">
<voicevoice _ item _ ref="Clarinetto _ I _ voice _ 1">
<chordevent _ ref="p5v1 _ 0">
<durationnum="1"den="4"/>
<augmentation _ dotsnumber="1"/>
<notehead>
<pitchstep="B"octave="5"/>
</notehead>
</chord>
<chordevent _ ref="p5v1 _ 1">
<durationnum="1"den="8"/>
<notehead>
<pitchstep="B"octave="5"/>
</notehead>
</chord>
<chordevent _ ref="p5v1 _ 2">
<durationnum="1"den="8"/>
<notehead>
<pitchstep="C"octave="6"actual _ accidental="sharp"/>
</notehead>
</chord>
<chordevent _ ref="p5v1 _ 3">
<durationnum="1"den="8"/>
<notehead>
<pitchstep="D"octave="6"/>
</notehead>
</chord>
</voice>
</measure>

logic description is encoded inside MX Logic
layer, whereas the digital image of a printed score
remains external and it is only linked and mapped
within Notational layer (see Figure 2).
Logic layer is composed of two sub-elements:
(1) spine, which lists the significant events refer-
able by other layers and (2) logically organized
symbols (LOS), that describes the score from a
symbolic point of view.
Spine has been illustrated and explained in the
previous sub-section. As regards LOS sub-layer,
it is based on the hierarchical structure typical of
XML formats. Generally speaking, music can be
considered strongly structured in a hierarchical
fashion: a complete score is made of pages, each
page of systems, each system of staves, each
staff of measures, and so on. Unfortunately, this
tree structure suffers from problems when ap-
plied both to staves and to instrumental parts. In

fact, the standard situation is having a biunique
relationship between staves and parts: a violin-
ist reads the violin staff, as well as a trumpeter
performs the notes written on the trumpet staff.
But pianists, harpists, and organists have their
part usually split into two or even three staves 4 .
These examples could suggest that staves are at a
lower level of instrumental parts in the hierarchy;
in other words, a score seems to be made of parts,
and each part takes one or more staves. But all the
scores represent a counterexample where many in-
strumental parts are written on the same staff: for
instance, flute and piccolo parts, or three different
melodic lines for as many horns. The solution is
providing two different structures and a device of
crossmapping: an instrumental hierarchy for parts
and voices and a layout hierarchy for systems and
staves. A part/voice will be assigned to a standard