A Brief History:
For a long time, mainstream American music has been a sequence of 4-bar (or multiples of 4-bar) phrases. In American Hip Hop, an 8 or 12 bar verse is followed by an 4 or 8 bar chorus. Usually popular dance music is a collection of longer multiples of 4-bar choruses (8 to 16-bar intro beats — 8 to 16-bar introduction of an instrument leaving a 32 to 64 bar segment before the heart of the song begins). Some “edits” only add an 8-bar intro while others also attempt to correct phrasing in the chorus or bridge even quantizing a track to perfect 4/4.
Why 8-Bar Intros?
Radio Edits usually not only correct the language, but the phrasing of a song to make it easy for a DJ to mix in. A Dj can start a new song with an 8-bar Intro at the start of an 8-bar chorus and drop to the new song perfectly. Before mp3s and programs with sampling/looping capability (I.E.: Serato’s Scratch Live or Native Instrument’s Traktor Pro) Vinyl compilations like Lethal Weapon, Ultimix, Wicked Mix, Fat Wax provided DJs not only with an easy collection of hits to play, but intro versions of the songs to make mixing much easier. Some DJs swear by them, others claim that it’s cheating, but the majority of DJs who quick mix drop them every day on the radio. It still is a no brainer that to give your track the best chance of being played by veteran or beginning dj is to have an 8-bar intro version of it.
8-Bar Intros and Asian Music?
Apart from engineering differences in recording style and mastering, Asian music does not always follow the 4-bar phrasing structure and deviates even further with beatless or off-tempo beginnings, forcing a dj to mix in on a looped hook, scratch it in, or simply fading into it causing a lapse in musical continuity. Even in different parts of America there are different schools of thought in terms of what is best, but no one can argue against the idea that beat continuity helps keep the flow. Some international music is not even in the 4/4 time signature (some Bhangra or Latin Music) forcing the concept of an 8-bar intro to act as the time signature transition from 4/4. A lot of K-Pop starts of with a beatless 4/4 signature that develops the song from a slow paced beginning to a faster paced theme (I.E. SNSD’s Gee or Genie). An intro edit that adds a beat not only makes it easier to mix, but more compatible to be mixed in with Western music. As the Hallyu wave continues it’s surge, more KPop has adopted the 4-bar phrasing structure and is released with an 8-bar introduction.
Is this relevant?
Many American fans of KPop are thrilled when hearing the original introduction to a song in order to set themselves up for the prescribed “dance.” This takes us back to the core dj skills of reading the crowd, knowing the music and how best to introduce and transition it for the crowd as well as integration into the set, and being able to recognize song structure so you don’t transition in the middle of a verse (which could be instrumental as well as vocal).