Tech Tip:Sample School: Sample-Based Loops: Part 1: The Origins of Loops
Back in the '70s, DJs used to spin two copies of the same record - usually a 45 RPM funk, soul or R&B single with a breakdown, or a 'break' in the middle - to extend or loop that passage of the song indefinitely, letting the dancers get into a steady groove on the floor, and providing a purely instrumental backing for MCs to pump the crowd and entertain on the microphone.
"Fantastic Freaks Live at the Dixie"
Today, this idea has permeated almost every layer of popular music. Many recordings are based upon a steadily-looping passage of drums sampled from another source, whether it be from the original recording, or from an isolated portion of the same beat from another artist's recording. In some records, the focus is solely on the drum loop, or 'break beat,' with other incidental sounds filling out the mix and providing variation.
"Biting My Nails" by Renegade Soundwave, 1989
In still other recordings, drum loops are used as a layer of percussion, buried in the mix of drums, but providing flavor and propelling the groove forward.
"Where Were You?" by Black Science Orchestra,1997
Though the roots of this technique are in hip-hop, it has spawned new styles of music (big beat, trip hop, drum and bass, etc.), and can be found in the most accessible of musical markets, such as Top 40 pop-music, Hollywood film soundtracks and television commercials. A positive result of this incorporation of breakbeats into the lexicon of popular music is that it is now easy for most musicians/producers/enthusiasts to experiment with their own sample-based loops. Whether they use drum samples to make their loops, or any other rhythmically-interesting source material, 'looping' is now commonplace.
There is commercially-available music sequencing software which is oriented toward sampling and loop-making, such as Steinberg's ReCycle, Sonic Foundry's Acid and Graysoft's Fruity Loops, just to name a few. There is also hardware that is designed to facilitate sample or 'phrase'-based loop creation, such as the Akai MPC-2000, Ensoniq ASR-X and the Roland SP-808, for example. Both software and hardware tend to have features which 'automate' some of the steps involved in making and using sampled loops. However, for practical purposes, I'll explain each step involved in this practice, as if you were going to do it manually, so that you can adapt them to your tool of choice - these guidelines remain the same, regardless of the method you choose to work with.