# Music Domain Entities

The Orchard's API for it's music domain is a graph of inter-linked entities. 
These entities represent those concepts you might find in any music domain. 
Others concern the visibility of those entities, as defined by The Orchard. 
This section groups the purely musical entities. 

##Channel
Represents a YouTube channel.  

##Chart
Platforms (Spotify, iTunes et al) produce Charts showing the popularity, in streams 
of the music people are listening to. We model these in our domain. 
Charts can be global or country specific. They are sometimes broken down by genre. 

##Label
Nearly all releases are associated with a Label.  Synonymous with Vendor, Labels are clients of The Orchard. 
Labels come in different flavors:
* D3 - an organisational or umbrella unit, comprising several Vendors. D3s do not actually release content themselves.
* Vendor - a 'vanilla' label.
* Subaccount - lives under a D3. 

##Participant
A participant is akin to an Artist. SoundRecordings must have participants. Participants can have one or more roles 
on a Sound Recording, and we are interested primarily in 'performer', 'remixer' or 'featuring'. 

##Product
A product is a theoretical concept that describes a release. It helps to think of Products as Albums or Singles.
Products have different formats (e.g. 12" vinyl, or CD), can be different in different regions, and be released under
different labels at different times. Products are referenced by a UPC.

##SoundRecording
Describes a master tape, or recording, of a piece of music. SoundRecordings are 
used (placed) on Tracks.  SoundRecordings are referenced by an ISRC and can be music or video.

##Track
A placement of a SoundRecording. Albums (Products) are comprised of Tracks. Singles have a Track.  One SoundRecording 
can appear on several Products as different Tracks. 

##Video
Represents a video in the YouTube world. As we are concerned with music videos regardless of platform, a Video entity
specifically refers to a YouTube video, whereas a SoundRecording with a type of 'video' represents a more generic video.