Introduction to the Music Encoding Initiative (MEI) DTD

1
Introduction to the Music Encoding Initiative
(MEI) DTD

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

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Purpose of the DTD

• encoding
• interchange

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Encoding

• not necessarily an input code, but still human
  readable (and understandable!)
• separation of logical, visual, gestural, and
  analytical domains
• declarative preferable to procedural
  representation
• formal verifiable
• interpreted all encoding is interpretation!
• explicit context independent
• flexible selective feature encoding
• extensible unknown uses, future development
• of particular interest musical form, text,
  critical apparatus

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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, mdiv)gt lt!ELEMENT mdiv (score,
parts)gt lt!ELEMENT score ((section, ending)
(bar, (pbsb)?))gt lt!ELEMENT pb EMPTYgt lt!ELEMENT
sb EMPTYgt lt!ELEMENT parts (part)gt lt!ELEMENT part
((section, ending) (bar, (pbsb)?))gt lt!ELEMEN
T section ((section, ending) (bar, (pbsb)?)
(strophe, strophe))gt lt!ELEMENT strophe
((section, ending) (bar, (pbsb)?)
(strophe, strophe))gt lt!ELEMENT ending
((section (bar, (pbsb)?)) (strophe,
strophe))gt lt!ELEMENT bar ((staff (beam
beatrpt btrem chord ftrem note pad
rest space tuplet) msrest msrpt
multirest multirpt), ossia, (arpeg beam2
bend dir dynam gliss hairpin
harm lyrics midi mordent octave pedal
phrase reh slur tempo tie trill
turn), (curve line symbol text),
annot)gt lt!ELEMENT staff (layer (beam
beatrpt btrem chord ftrem note pad
rest space tuplet) msrest
msrpt)gt lt!ELEMENT layer ((beam beatrpt btrem
chord ftrem note pad rest space
tuplet) msrest msrpt)gt
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Document element

• mei (meihead, work) encodes a single work
• separates document into meta-data and 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 meta-data for the file
• filedesc element contains bibliographic data,
  such as title, agent, and publication status, and
  access data, such as vendor, price, and rights
  management info, for the file
• sourcedesc element describes a source for the
  file using the same elements as filedesc, but
  also includes physical description, such as
  medium, dimensions, provenance
• name cannot be changed in order to assure an
  absolute minimum level of MEI compliance

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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
• names cannot be changed in order to assure an
  absolute minimum level of MEI compliance

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music element

• the musical, as opposed to the textual, part 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
  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 sourcedesc 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
• it is not always possible or desirable to
  generate one view from the other
• views 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

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part element

• requires all the encoding features of a full
  score content models of score and part
  elements are identical
• part elements in MEI have nothing to do with
  voice-leading, that is, indicating how a part may
  be constructed when it uses more than one staff
  or when there are multiple voices on a single
  staff
• voice-leading may be recorded at the event level
  using the next or prev attribute

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part element, cont.

• use of parts practical 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 software that requires
  staff-by-staff encoding

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section element

• part or score 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
• may also be used for user-defined, that is,
  analytical or editorial, purposes
• may be arbitrarily nested to any level
• 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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strophe and ossia elements

• basis of critical apparatus
• used for encoding more than one version in the
  same file
• strophe used at section level, ossia at bar level
• nested to accommodate variants of variants?
• more work to do!

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ending element

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

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bar 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
• also contains control events, that is, those
  which do not fit the principal hierarchy, such as
  dynamics, ties, and phrase marks

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staff and layer elements

• provided in order to indicate division of the
  bar's contents into multiple data streams
• ltbargt
• ltstaffgtltnote /gtlt/staffgt
• ltstaffgtltnote /gtlt/staffgt
• lt/bargt
• do not necessarily indicate layout!
• alternatively, events may be encoded directly
  within the bar element and each event may be
  related to a particular data stream via its staff
  and layer attributes
• ltbargtltnote staff"s1" /gtltnote staff"s2"
  /gtlt/bargt

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Introduction to the Music Encoding Initiative
(MEI) DTD

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