Trance is a style of electronic ance music that developed in the 1990s. Trance music is generally characterized by a tempo of between 130 and 160 BPM, short melodic synthesizer phrases, and a musical form that builds up and down throughout a track. Trance can be understood as a combination of many forms of electronic music such as ambient, techno, and house. The origin of the term is ambiguous, with some suggesting that the term is derived from the Klaus Schulze album Trancefer (1981) or the early trance act Dance 2 Trance. In any case, the name is undoubtedly linked to the perceived ability of a drum beat to induce altered states of consciousness known as trance. The effect of some trance music has been likened to the trance-inducing music created by ancient shamanists during long periods of drumming. As this music is frequently played in nightclubs, vacation spots and inner cities, trance can be understood as a type of club music.