Concept album
A concept album is an album consisting of songs that are consistently about a specific theme. It can verge on operatic narrative, telling a cohesive story, with each song providing a further glimpse into the whole picture, or even furthering the plot as a miniature form of episodic fiction.
The Nine Inch Nails double album The Downward Spiral is a good example of a concept album, not only depicting the narrator's disillusionment with religion and his descent into depression and hatred, but also employing leitmotif, with the titular song's main melody being warped and echoed throughout the album.
There are no hard rules. The Prodigy's double album Music for the Jilted Generation has a theme specifically just for its D side, "The Narcotic Suite".
There's no strict definition of a concept album. Most people consider Sgt. Pepper's Lonely Hearts Club Band to be a canonical example of one. This is presumably because it has good flow, two variations of the title song that more or less bookend it, and cover artwork depicting the band as the fictitious versions of themselves that the album's named after. However, the other eleven songs have nothing to do with this theme, making its status as a concept album debatable.
Just as the tracks or songs of an album work together much like the movements of a concerto or symphony, and indeed the first albums were literally recordings of entire concerti and symphonies, concept albums are essentially an evolution of program music. You could make a good argument that, in retrospect, one of the earliest examples of a concept album is Vivaldi's Four Seasons, recorded onto an album of 78s.
Release types: Concept album
