Music Discovery Requirements

II.D Musical Works: Medium of Performance

Medium of performance is an attribute uniquely important to music. It is an identifying element for known musical works, and users also regularly seek works and expressions for a particular medium of performance, without a particular work/expression in mind at the beginning of their search. However, historically, data recording and encoding standards and practices have not made medium of performance cleanly and consistently separable from other attributes. The Library of Congress Medium of Performance Thesaurus (LCMPT) was only launched in 2014.[1]

In current practice, medium of performance information is/may be recorded in MARC 382 using terms from LCMPT.[2] In MARC/AACR2 legacy data, the medium of performance may be stated or implied in fields for title (130, 240, 7xx) or subject/genre (650/655), encoded in 048 (medium of performance), or implied to a limited degree in certain codes in 008/18-19 and 047 (form of composition). Medium of performance may also be mentioned or implied in various descriptive fields (245, 246, 250, 500, 505, 511). Descriptive fields are particularly important for recordings, especially for jazz and popular music, where the only explicit medium of performance information may be in a listing of performers and their instruments in field 511. In the future, legacy data might be massaged so that medium of performance contained in 650 is moved to 382.

Rules governing input of certain fields or elements within LCSH and RDA authorized access points representing the musical work/AACR2 uniform titles add to the problem of limited or dispersed information. This is particularly problematic with vocal music, folk music, recorded popular music, and compilations. Indexing, displaying, and allowing limits/facets by multiple fields will maximize users’ ability to search for and identify medium of performance.

Going forward, configuring discovery interfaces to utilize LCMPT vocabulary encoded in MARC 382 is essential, as is massaging legacy data to ensure uniform presence of the field. LCSH patterns have many shortcomings: combination of genre/form with medium of performance in a single term, difficulty in identifying soloists and number of performers, the semantic relationships between terms, and the syntax of the terms. MARC 048 is also problematic, particularly for recorded popular, jazz, and folk music when some, but not all, mediums can be identified. Now that 382 is defined and in use, strongly consider suppressing 048 when 382 is present, and focus development efforts on 382 data.

Challenges relating to medium of performance are further complicated by the prevalence of manifestations containing multiple expressions. (For additional discussion, see Compilations in IV.C.) Linking fields offer a potential solution in this area but have historically not been employed.

Users may also seek an expression with a particular medium of performance (i.e., an arrangement). See III.G for further discussion.

Recommendation: Index and display fields relating to medium of performance, with codes converted to the vernacular. Explore alternative tools and interfaces to allow users to interact more easily with medium of performance. For detailed display recommendations for MARC 382 Medium of Performance information, see the WorldCat Discovery Display Preferences for Medium of Performance from the Music OCLC Users Group.[3]

Index and Display (Bibliographic/Descriptive Metadata):

MARC: 048 Number of Musical Instruments or Voices Code (display code in vernacular; use only if 382 is not present)

MARC: 130 $m; 240 $m; 7xx $m Medium of performance for music

MARC: 382 Medium of Performance. See WorldCat Discovery Preferences for Medium of Performance from the Music OCLC Users Group for detailed recommendations.

MARC: 505 Formatted Contents Note

MARC: 511 Participant or Performer Note

MARC: 650 Subject Added Entry - Topical Term

Dublin Core: type

EBUCore: hasGenre, hasSubject (if using LCSH)

MODS: subject (if using LCSH)

PBCore: pbcoreSubject (if using LCSH)

BIBFRAME 2.0: Classes: bf:MusicMedium, bf:MusicInstrument, bf:MusicEnsemble, bf:MusicVoice; Properties: bf:ensemble, bf:ensembleType, bf:instrument, bf:instrumentalType, bf:musicMedium

Facets/Limits (Bibliographic/Descriptive Metadata):

MARC: 048 Number of Musical Instruments or Voices (display code in vernacular)

MARC: 382 Medium of Performance

MARC: 650 Subject Added Entry--Topical Term

EBUCore: hasGenre, hasSubject
MODS: subject

PBCore: pbcoreSubject (if using LCSH; LCSH is not a valid vocabulary for pbcoreGenre)

BIBFRAME 2.0: Classes: bf:MusicMedium, bf:MusicInstrument, bf:MusicEnsemble, bf:MusicVoice; Properties: bf:ensemble, bf:ensembleType, bf:instrument, bf:instrumentalType, bf:musicMedium

Medium of performance information may be too complex to use as a limit/facet within a general search interface. Before LCMPT and MARC 382, several institutions developed separate, complementary search tools utilizing MARC 048 data. These tools are provided as examples of functionality, though these tools may undergo revisions in the near future, such as to employ LCMPT and MARC 382 data.

Kent State:

University of North Texas:

Ball State: (the Chamber Music finder)[4]

Note: The Ball State search relies on detailed encoded information drawn from a non-MARC thesaurus. The addition of IAML medium of performance codes to MARC codes provides a high level of specificity, but the IAML thesaurus is not widely used in the United States.[5]

Related MARC Authority Fields:

MARC: 100 $m; 130 $m; 150; 155; 382.

[1] LCMPT terms were first available for assignment on February 25, 2014. The MLA Vocabularies Subcommittee released provisional Best Practices for Using LCMPT on April 7, 2014, and non-provisional “Revised and Expanded” Best Practices for Using LCMPT on February 22, 2016 and again on February 14, 2017. See most current version at:

[2] MARC 382 was defined in MARC Update 14, April 2012. Further changes to 382 were made in MARC Update 20 (added $e Number of ensembles (R) and MARC Update 22 (added $r Total number of individuals performing alongside ensembles (NR); added $t Total number of ensembles (NR); renamed $e to Number of ensembles of the same type). MLA’s Best Practices documents do not yet reflect the most recent additions, but will be updated to do so in the future.

[3] Music OCLC Users Group, “Discovery, Reference, and Collections,” accessed August 25, 2017,

[4] For details on the development of Ball State’s Media Finders, see Kelley McGrath, “Media Finders: Improving the Browsability of Media Collections via the OPAC,” Internet Reference Services Quarterly 11, no. 3 (2006): 19-34. Though written before the Chamber Music finder was developed, the underlying processes are the same.

[5] See “UNIMARC field 146 - Medium of Performance” for further information on these codes, from the International Association of Music Libraries, Archives and Documentation Centres (IAML). See also search interface at Retrieve a complete list by selecting "Display all terms":