UserLibrary as ul
-
UserID PK varchar
SavedTracks array # array of track ID's (varchar)

ArtistName
-
TrackID PK varchar FK >- ul.SavedTracks
ArtistName varchar

AudioFeatures
-
TrackID PK varchar FK >- ul.SavedTracks
Danceability decimal
Energy decimal
Loudness decimal
Speechiness decimal
Acousticness decimal
Instrumentalness decimal
Valence decimal
Tempo decimal

Genre
-
TrackID PK varchar FK >- ul.SavedTracks
MainGenre NULL varchar
OtherGenres NULL array

Popularity
-
TrackID PK varchar FK >- ul.SavedTracks
Popularity decimal

Runtime
-
TrackID PK varchar FK >- ul.SavedTracks
Runtime smallint # seconds

TrackName
-
TrackID PK varchar FK >- ul.SavedTracks
TrackName varchar

Year
-
TrackID PK varchar FK >- ul.SavedTracks
Year smallint