Music Encoding Initiative (MEI) DTD and the OCVE

1
Music Encoding Initiative (MEI) DTD and the OCVE

• Perry Roland
• Digital Library Research Development Group,
  Alderman Library, University of Virginia
• pdr4h_at_virginia.edu
• http//www.people.virginia.edu/pdr4h

2
Purposes of the DTD

• encoding
• interchange

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Encoding

• not necessarily an input code, but still human
  readable (and understandable!)
• declarative preferable to procedural
  representation
• formal verifiable
• explicit context independent
• flexible allows selective feature encoding, can
  be constrained, separates visual, gestural, and
  analytical domains
• extensible for unknown uses, future development
• of particular interest musical form, text,
  critical apparatus

4
Interchange

• comprehensive generalized
• software independent
• N(N-1) vs. N2 translators

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Basic MEI DTD
lt!ELEMENT mei (meihead, work)gt lt!ELEMENT
meicorpus (meihead, mei)gt lt!ELEMENT meihead
(meiid, filedesc, projectdesc?, editorialdecl?,
profiledesc?, revisiondesc?,
sourcedesc)gt lt!ELEMENT work (front?,
(musicgroup), back?)gt lt!ELEMENT group
((workgroup), (workgroup))gt lt!ELEMENT music
(mdiv)gt lt!ELEMENT mdiv (score?,
parts?)gt lt!ELEMENT score (div, (section,
ending, div) (measure?, (pbsb)?))gt lt!ELEM
ENT parts (part)gt lt!ELEMENT part (div,
(section, ending, div) (measure?,
(pbsb)?))gt lt!ELEMENT section (div, (section,
ending, div) (measure?, (pbsb)?) staff
app)gt lt!ELEMENT app (rdg, rdg)gt lt!ELEMENT
rdg (div, (section, ending, div)
(measure?,(pbsb)?) staff app)gt lt!ELEMENT
ending (div, (section, ending, div)
(measure?,(pbsb)?) staff
app)gt lt!ELEMENT measure (((staff (beam
beatrpt btrem chord ftrem note pad
rest space tuplet) layer (msrest
msrpt multirest multirpt)?)), ossia, (annot
arpeg beam2 bend dir dynam gliss
hairpin harm lyrics midi mordent
octave pedal phrase reh slur
tempo tie trill turn), (curve line
symbol ))gt
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Document element

• mei (meihead, work) encodes a single work
• separates document into data and meta-data parts,
  allowing meta-data to be shared with other
  internal and external entities
• name cannot be changed in order to assure an
  absolute minimum level of MEI compliance

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Alternate document element

• meicorpus (meihead, mei) encodes multiple mei
  instances where each requires a header of its own
• also provides header for entire file
• name cannot be changed in order to assure an
  absolute minimum level of MEI compliance

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meihead element

• encodes bibliographic (descriptive,
  administrative, and technical) meta-data for the
  file
• filedesc element contains data, such as title,
  agent, and publication status, and access data,
  such as vendor, price, and rights management
  info, for the file
• sourcedesc element contains descriptions of each
  source for the file. source elements employ the
  same bibliographic elements as filedesc, but also
  include physical description elements, such as
  medium, dimensions, provenance, inscription,
  condition, etc.

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work element

• the "thing" being encoded
• may include not just music notation, but also the
  textual matter often found in a critical or
  historical edition, composer's textual notes,
  advertisements, etc.
• name cannot be changed in order to assure an
  absolute minimum level of MEI compliance

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Work-level text

• front and back child elements provide basic
  logical and presentational text markup
  functionality
• accommodating text gives control of the text and
  notation to MEI, which embedding notation in
  another markup scheme, such as TEI, will not do

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music element

• encodes the musical, as opposed to the textual,
  content of the work
• contains highest-level indication of the
  structure of the composition one or more
  discrete, linear segments, called mdiv ("musical
  division")
• generic mdiv elements may be typed symphonies,
  for example, usually consist of movements while
  operas are made up of acts

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group element

• facilitates creation of a collection of work
  elements that share a bibliographic header a
  collection of songs by different composers issued
  under a single title, for example
• basic meta-data for each work may be encoded in
  its own front matter or in source elements in the
  file header
• use meicorpus element when a complete
  bibliographic header is required for each member
  of a collection

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mdiv element

• may contain one or both of two possible
  organizing views score and parts
• score element contains a time-oriented view of
  the composition a full score
• parts element contains part elements each of
  which represents a performer's view

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mdiv element, con't.

• score and parts views are intended to accommodate
  different methods of organizing the markup no
  particular presentation is implied, software may
  render a collection of parts as a score or a
  score as a collection of parts
• it is not always possible or desirable to
  generate one view from the other. A great deal of
  complexity can be eliminated by separating score
  and part markup.

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part element

• has all the encoding features of a full score
  content models of score and part elements are
  identical
• voice-leading should be recorded at the event
  level using the next or prev attributes

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part element, cont.

• use part elements when
• there is no score, only a collection of parts
• parts don't share visual characteristics, such as
  typeface or layout with the full score or with
  each other
• score has non-aligning bar lines
• accommodating rendering software that requires
  staff-by-staff encoding

17
section element

• score or part may be divided into linear segments
  or sections
• ?sections usually function as scoping mechanisms
  for clef signs, key and meter signatures, and
  expression marks
• minimize the need for backward scanning to
  establish context when the starting point for
  access is not at the beginning
• when a section contains sections, the expan
  attribute on the outer section element may be
  used to encode the performance order of the inner
  sections

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section element, con't.

• may also be used for user-defined, that is,
  analytical or editorial, purposes
• may be arbitrarily nested to any level

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app and ossia elements

• an app element contains at least one alternative
  reading
• each rdg may be linked to a source description in
  the header
• rdg may contain app so that variants of variants
  may be described
• each rdg may be assigned an order, e.g. for
  selection or rendering purposes, other than the
  encoded order
• ossia performs a similar function at the measure
  level, however, it represents an alternative
  present in the source being transcribed.

20
ending element

• specialized form of the section element that may
  not be recursively nested

21
measure element

• contains events, not symbols
• even though events have visual properties,
  modeling symbols places too much emphasis on
  presentation and makes the markup less useful as
  a general "music" (as opposed to "notation")
  markup scheme
• is a linking element that connects the MEI
  document to an external electronic object, i.e.,
  image, or to another location within the current
  MEI instance

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Control events

• control events, such as dynamics, ties, phrase
  marks, pedal marks, etc. depend on other events
• do not fit the principal hierarchy of sections,
  measures and staves
• multiple control events of the same type, i.e.,
  pedal indications, may be associated with the
  same set of events, i.e., notes

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staff element

• may be used to indicate division of the measure's
  contents into multiple data streams
• ltmeasuregt
• ltstaff def"1"gtltnote /gtltrest
  /gt...lt/staffgt
• ltstaff def"2"gtltnote /gtlt/staffgt
• lt/measuregt
• does not necessarily indicate layout!
• in a staff-by-staff encoding, staff may contain
  measure elements
• ltstaffgt
• ltmeasure n"1"gt...lt/measuregt
• ltmeasure n"2"gt...lt/measuregt
• lt/staffgt
• ltstaffgt
• ltmeasure n"1"gt...lt/measuregt
• ltmeasure n"2"gt...lt/measuregt
• lt/staffgt

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Music Encoding Initiative (MEI) DTD and the OCVE

• Perry Roland
• Digital Library Research Development Group,
  Alderman Library, University of Virginia
• pdr4h_at_virginia.edu
• http//www.people.virginia.edu/pdr4h