• remind me tomorrow
  • remind me next week
  • never remind me
Subscribe to the ANN Newsletter • Wake up every Sunday to a curated list of ANN's most interesting posts of the week. read more

Original Soundtrack (OST)

The music used in a show. This includes background music, mood music, incidental music and opening and ending theme music. For longer TV series, there is often too much music to release on a single CD, so several OSTs will be released (often called OST1, OST2, etc.)

Typically, due to time restrictions, shows only use a portion of any particular piece of music, however the OST generally will contain the entire piece, giving fans an opportunity to listen to the music in its entirety.

There are exceptions; some OSTs only contain "TV-size" versions of the music, and some OSTs don't contain certain pieces of music, including, on occasion, the theme songs. Lack of the theme song generally has to do with licensing restrictions.

Theme Music occurs either as Opening Theme (OP) or Ending Theme (ED). These are songs or music that occur while the opening or ending credits are rolling, and which serve to set a mood for the anime. Though they are sometimes not written originally for the anime, they tend to become strongly associated with it in the public mind.

Incidental Music (IM), also called "insert songs" or "featured songs", are songs or musical pieces that occur within the body of the anime. They differ from Background Music (BGM) in the amount of "attention" they are given - for instance, there is seldom any dialogue over IM, whereas dialogue frequently occurs over BGM.

Image Albums contain music composed on the basis of screenplay, long before anime production begins. The composer reads through the outline of the story, and composes music based on his / her feelings and imagination. Many scores from Image Albums will be incorporated into OST after being revised to match the animation.

Anime OSTs and Image Albums have long been heavily bootlegged. Up until recently, very few OSTs were licensed in North America, and imports from Japan are quite expensive. Demand, resulting from the growing popularity of anime, and the lack of a legitimate and affordable supply, resulted in a market that was very attractive and open to bootlegging. Even now (2004) the majority of anime OSTs are not licensed in North America and illegal copies of the Japanese OST releases continue to be widely available.

return to lexicon