An album or record album is a collection of related audio or music tracks distributed to the public. The most common way is through commercial distribution, although smaller artists will often distribute directly to the public by selling their albums at live concerts or on their websites.
The tracks on an album may be related by subject, mood or sound, and may even be designed to express a unified message or tell a story (as in the case of a concept album), or the tracks may simply represent a convenient grouping of recordings made at one time or place, or recordings whose commercial rights are controlled by a single record label. A group of audio tracks is considered to be an album if it has a generally consistent track list (often with minor differences or bonus tracks in different territories, or if the album is "reissued" at different times). An album may be released in a single format, such as on compact disc, or in multiple media formats, ranging from physical ones such as CDs, DVD audio, cassettes and vinyl records, to digital ones such as MP3 and AAC files or streaming audio.
The term "record album" originated from the fact that 78 RPM Phonograph disc records were kept together in a book resembling a photo album. The first collection of records to be called an "album" was Tchaikovsky's Nutcracker Suite, released in April 1909 as a four-disc set by Odeon Records. It retailed for 16 shillings — about £56 (US$101) in 2005 currency.
In 1948, Columbia Records produced the first 12 inch, 33⅓ RPM microgroove record made of vinyl. With a running time of 23 minutes per side, these new records contained as much music as the old-style album of records and, thus, took on the name "album". For many years, the standard industry format for popular music was an album of twelve songs, originally the number related to payment of composer royalties.
Traditionally, an album ranged in duration from half an hour to an hour, depending on the genre and record label. American pop albums tended to be around a half hour; British pop albums were somewhat longer, often containing 14 songs instead of 11 or 12; jazz albums were longer still; and classical albums were the longest of all. From the dawn of the "album era" (in jazz, about 1954; in rock, about 1962) until about the mid-1960s, albums were often recorded as quickly as possible, sometimes in single sessions. (Prestige Records and Blue Note Records were famous for this; as well, the Beatles' first album and the Byrds' first four albums were all largely recorded in single sessions.)
Vinyl LP records had two sides, each comprising one half of the album. If a pop or rock album contained tracks released separately as commercial singles, these were often traditionally placed in particular positions on the album. A common configuration was to have the album led off by the second and third singles, followed by a ballad. The first single would lead off side 2. In the past, many singles (such as the Beatles' "Hey Jude") did not appear on albums, but others (such as the Beatles' "Come Together" and "Something") were also part of an album released concurrently. Today many commercial albums of music tracks feature one or more singles, which are released separately to radio, TV or the Internet as a way of promoting the album. Albums have also been issued that are compilations of older tracks not originally released together, such as singles not originally found on albums, b-sides of singles, or unfinished "demo" recordings.
Today, with the vinyl record no longer being used as the primary form of distribution, the term "album" can still be applied to any sound recording collection, such as those on compact disc, MiniDisc, Compact audio cassette, and digital or MP3 albums. Cover art is also considered an integral part of the album. Many albums also come with liner notes and inserts giving background information or analysis of the recording, reprinted lyrics, images of the performers, or additional artwork and text. These are now often found in the form of CD booklets.
Due to the large capacity of new media (compact discs originally ran to 74 minutes, later extended to 80 minutes) and the lack of any formal "side" divisions, the matter of how long an album should be is open to debate, although most albums today are at least 30 minutes long. Usually, rock albums with a particularly fast tempo, such as albums in punk rock and non-progressive thrash metal are the shortest, then albums in mainstream rock and pop; then hip hop albums are the longest. According to the rules of the UK Charts, a recording counts as an "album" if either it has more than four tracks or lasts more than 25 minutes. Sometimes shorter albums are referred to as EPs, an abbreviation of extended play, "extended" meaning longer than a single but shorter than an LP. The term "mini-album" may also be used.
If an album becomes too long to fit this format, a recording artist may make the decision to release a double album where two vinyl LPs or compact discs are packaged together in a single case, or a triple album containing three LP's or compact discs.
Recording artists who have an extensive back catalogue will often re-release several CDs in one single box with a unified design, often containing one or more albums, or a compilation of previously unreleased recordings. These are known as box sets. Some musical artists have also released more than three compact discs or LP records of new recordings at once, in the form of boxed sets, although in that case the work is still usually considered to be an album.