Key Concepts and Terminology
GMD API endpoints (type)
Artist (artists)
A recording artist with a unique identity and billing. An Artist may be an individual, group, ensemble, or collaboration of any of these. An Artist creates Recordings. Recordings are then released as Album Tracks on one or more Albums Editions.
Album Edition (albumEditions)
An Album Edition is a specific Edition of an Album Master - comprised of a unique configuration of Recordings.
Recording (recordings)
A perceptually unique audio Recording. Various individual Album Track instances that have been released of the same Recording are identified as perceptually identical by comparing metadata and acoustic fingerprints. All such Album Track instances map to the same Recording ID and descriptive profile.
Lookup, Search, and Explore
GMD API provides three ways to query for GMD data:
Lookup: Gets artist, album edition, and recording endpoints using Gracenote IDs. You can also use Streaming Service IDs to look up album editions and recordings, and Gracenote Celebrity Person IDs for artists.
Search: Gets artist, album edition, and recording endpoints using text searches.
Explore: Gets a list of artists, album editions, or recordings that are sortable, and filterable using metadata properties like genre and popularity.
Data Types Within GMD API endpoints
Factual Data
Factual or core metadata includes identifiers and names of the Artists, Albums, and Recordings. The album endpoint also includes the release year, number of tracks, and ordinal.
Association Types
Associations indicate the relationships among Artists, Album Editions, and Recordings.
Alternate Names alternateNames
Alternate names are names that the artist/group has recorded under. This includes differently styled names in billing, cover art, official merchandise, and so on. Alternate names are not used where an artist creates an alternate persona. For example, Garth Brooks releasing material under the alternate persona of Chris Gaines creates a unique artist ID for alternate persona, instead of an alternate name for Garth Brooks.
Group Members (groupMembers)
For Artists of endpointType``Group, Member is the relational association to the Artist IDs of individual members of a named group.
Collaboration Members (collaborationMembers)
For Artists of endpointType``Collaboration, Collaboration Members is a relational association to the Artist IDs of a collaboration. For example, 2Pac Feat. Snoop Doggy Dogg, Nate Dogg & Dru Down. Each is a collaborationMember of the Collaboration.
Disambiguation (disambiguation)
The Artist Disambiguation field includes information that can be useful to differentiate artists with identical names, using editorial Genre and Origin data to easily display disambiguation. This field is only available in English currently.
Key Artists (keyArtists)
A core artist may have released material under more than one ensemble name, yet all of these are considered part of the core artist’s body of work. In these cases, for Artists of endpointType “Group, “Has Key Artist” is the relation association to the Artist ID of the Individual Artist who is the leader of the ensemble. This facilitates unified presentation of the complete body of work. For example, Prince is a key artist in Prince & The Revolution, and Miles Davis is a key artist in the Miles Davis Quintet.
Member Of Groups (memberOfGroups)
For Artists of endpointType Group, memberOfGroups is the relational association to Artist ID of a named group.
Member Of Collaborations (memberOfCollaboration)
Lists all the collaborations for an Artist.
Name Variants (nameVariants)
Name Variants can include full name, birth names, misspellings, nicknames, etc.
Artist endpoint Type (artistendpointType)
Artist endpoint Type describes whether an artist is an individual, group or collaboration. A collaboration may combine two or more individuals and or groups.
Similar Artists (similarArtists)
Similar artists is an editorially assigned field that associates artists that are significantly stylistically like one another. Most of the similar artists may have a similar primary genre.
Stylistic similarity may be of one or more of the following:
- Similarity of musical style: The overall musical character / “gestalt” that is formed from the combination of various musical elements in the artist’s recordings:
- Similar genre or combination of genres (high-level)
- Similar mood or combination of moods (high-level)
- Similar musical characteristics, including chord progressions, melodic style, instrumentation (both tonal and percussive), timbres, rhythm type, vocal style and intonation, playing style, harmony/modes/scales, arrangements and overall production style.
- Similarity of lyrical style: Lyrical style includes similar topics, worldview, attributes, personality, mood, vocabulary, slang, dialect, language.
- Similarity of visual aesthetic: Similarity in cover art, logos, posters & other visual content; video, film, TV, concert style and production design; fashion (e.g., clothing, hairstyle, make-up); physical characteristics
Sort Name (sortName)
You can use sortName to efficiently organize and manage lists of Artists:
- Artists: ‘Family name, First name’, for example “Swift, Taylor”.
- Artists of type Group: “Group name, Article”, for example “Beatles, The”.
Descriptors
Descriptors indicate characteristics of an artist, album edition, or recording to help drive use cases such as catalog organization, discovery, and analytics. There are currently eight descriptor types:
- Artist-level Descriptors: Genre, Language, Origin, Era, Artist Type
- Recording-level Descriptors: Sonic Mood, Sonic Style, and (Perceived) Tempo (hereafter referred to as Tempo).
Descriptor Value (weight)
A weighted descriptive attribute of an Artist or Recording. Gracenote editorial staff assign Artist-level Descriptors. Machine listening processes trained from the same expert editorial knowledge assign Recording-level Descriptors.
- There can be up to 10 different descriptors of the same type assigned to a single Artist, Album or Recording endpoint.
- For Genre, Language, Origin, Era, Artist Type, and Tempo, the weights of all descriptors of the same type assigned to a single Recording or Artist entity will add up to approximately 100.
- For Sonic Mood and Sonic Style, the sum of the descriptor weights may sometimes add up to less than 100, due to the full vector extending beyond the 10 most relevant positions published in the GMD API.
- For a given entity, the descriptor with highest weight for each descriptor type is considered the “primary descriptor” for that type.
Genre (genres)
Genre describes the musical style of the Artist, Album, or Recording. Each Artist, Album and Recording may have one or more Genres assigned, each with a weight associated with it, indicating its relative relevance for that entity. Gracenote’s international team of editors select from a controlled vocabulary of Genre descriptors values in making these assignments. The combination of genre descriptor values and their weights that are assigned to an Artist, Album, or Recording are referred to as their “Genre Profile”. A specific Album or Recording's primary Genre may be different from that of its album or recording Artist.
Language (languages)
Artist Language indicates the languages in which the artist has recorded in. Each artist may have one or more languages assigned, each with a weight associated with it that indicates its relevance for that artist.
Origin (origins)
Origin indicates the geographic region(s) with which the recording artist is most strongly associated. Note that this is not necessarily their birthplace or country, but rather the music scene with which they are most strongly linked. Most Artists have just a single origin assigned, though some do have more than one.
Era (eras)
Era indicates the time period(s) in which the artist created its most relevant recordings. This is editorially determined based on a combination of when the Artist recorded most of their work, and when, within that range, the Artist’s best-known and most critically – acclaimed Recordings were made. Era profiles include weight assignments, which indicate the relative importance of different periods within the Artist’s career. This enables accurate description of Artists whose active recording period spanned multiple periods.
Artist Type (artistTypes)
Indicates the configuration in which the artist typically performs. This is described in terms of Artist Grouping (Solo, Duo, Group), Artist Gender Composition (Male, Female, Non-Binary, Mixed), Instrumentation (Vocal, Instrumental), Vocal Grouping (Solo, Duo, Group), and Vocal Gender Composition (Male, Female, Non-Binary, Mixed).
Sonic Mood (moods)
For each Recording, the (up to) ten strongest Moods detected (out of the 400+ Sonic Mood classes) are included in the GMD API. Depending on how many different significant Moods are detected in the Recording, 1 to 10 Mood Descriptor Values will be provided. Each one is assigned a weight indicating how much out of a total of 100 points is attributable to that Mood for the recording.
The “Primary Mood” is the most prominent Mood detected across the duration of the Recording. This determination is made according to the relative strengths of each Mood detected through supervised machine listening and heuristics.
Sonic Style (styles)
Sonic Style describes musical style elements detected in a Recording using machine learning, based purely on the nature of the recording audio itself, and are different from Artist Genres, which describe the musical and cultural context of an artist and are assigned editorially.
Tempo (tempos)
Tempo indicates the 3 most perceptually relevant beat rates detected in the Recording. Each rate also has a weight associated with it which indicates its relative relevance across the curation of the Recording. Tempo Descriptor Values correspond to beat rates from 0 to 300+ BPM in 10s. The “Primary Tempo” is the most prominent Tempo, as determined through analysis and heuristics.
Album Release Type (releaseType)
Release Type applies to Albums and indicates whether it is an original release or a single artist’s greatest hits, various artists compilation, or other release type. This field can be used for filtering and ordering, for example, to prefer the track instances of a desired Recording on a Main Canon Album over alternate track instances of the same source Recording on a Various Artists Compilation.
| Release Type | Description |
|---|---|
| Main Canon Collection | An original album by multiple artists Example: Saturday Night Fever Soundtrack |
| Single / EP | A commercially available Single release Example: Borderline [Maxi Single] |
Descriptor Hierarchical Data Structures
Descriptor Hierarchies enable the presentation of the information contained in the Descriptor Values in simpler, more user-friendly display categories. The Descriptor Hierarchies are not used for calculating artist or recording similarity, but rather for categorical display, organization, and navigation in the end-user UX.
There is a single Descriptor Display Hierarchy for each of the following Descriptor Types: Origin, Era, Artist Type, Sonic Mood, Sonic Style, and Tempo. For Genre, however, there are a total of 17 Hierarchies. This is because to provide the best user experience across the globe and each application use case, Gracenote provides regionally appropriate genre hierarchies for each of 9 international regions - and for each of these regions except for India, which only has a Simplified Hierarchy, a Simplified and a Detailed version is available.
Additionally, all display category hierarchy nodes are localized and translated into over thirty languages.
It is important to keep in mind that regardless of which of the 17 Genre Hierarchies is presented to an end user, and which localization strings are displayed, all source data at the Descriptor Value level utilizes the same controlled vocabulary. That is, there is only a single set of Descriptor Values used by Gracenote editors and machine listening systems worldwide, and all annotations are made using this single controlled vocabulary. This ensures that the semantic integrity of all descriptive data is always maintained globally.
Additional Data Elements
Person ID (personID)
Gracenote Celebrity PersonID at the artist level and is associated with artistendpointType of persons, which allows for the possibility to link artists from Gracenote’s Global Music Data to other Gracenote datasets, which include:
- Podcasts: Audio on Demand (AOD)
- Video: On API
Popularity Score (popularity)
Score on a scale of 0 to 1 which is derived from streaming consumption data from a given breakout, for a given period, for Artists and Recordings. Popularity Scores are available for Artists and Recordings only and can be licensed via zones aligned with the United Nations geoscheme. Corresponding breakout sets are associated with each of the zones.