'Break-beat music and hip-hop culture were happening at the same time as the emergence of disco (in 1974 known as party music). Disco was also created by DJs in its initial phase, though these tended to be club jocks rather than mobile party jocks..... records by Barry White, Eddie Kendricks and others became dancefloor hits in New York clubs like Tamberlane and Sanctuary and were crossed over onto radio by Frankie Crocker at station WBLS. There were many parallels in the techniques used by Kool DJ Herc and a pioneering disco DJ like Francis Grasso, who worked at Sanctuary, as they used similar mixtures and superimpositions of drumbeats, rock music, funk and African records. For less creative disco DJs, however, the ideal was to slip-cute smoothly from the end of one record into the beginning of the next. They also created a context for breaks rather than foregrounding them and the disco records which emerged out of the influence of this type of mixing tended to feature long introductions, anthemic choruses and extended vamp sections, all creating a tension which was released by the break. Break-beat music simply ate the cherry off the top of the cake and threw the rest away. In the words of Grandmaster Flash...

'Disco was brand new then and there were a few jocks that had monstrous sound systems but they wouldn't dare play this kind of music. They would never play a record where only two minutes of the song was all it was worth. They wouldn't buy those types of records. The type of mixing that was out then was blending from one record to the next or waiting for the record to go off and wait for the jock to put the needle back on.''
- Grandmaster Flash - 1984 - by David Toop. Rap Attack 2, 62. New York: Serpent's Tail.

A scratch is nothing but the back-cueing that you hear in your ear before you push it out to the crowd. All you have to know is mathematically how many times to scratch it and when to let it go..... when certain things will enhance the record you're listening to. For instance, if you're playing a record with drums... horns would sound nice to enhance it so you get a record with horns and slip it in at certain times.
- Grandmaster Flash - 1991 - by David Toop. Rap Attack 2, 65. New York: Serpent's Tail

Herc really slipped up. With the monostrous power he had he couldn't mix too well. He was playing little breaks but it would sound so sloppy. I noticed that the mixer he was using was a GLI 3800. It was a very popular mixer at that time. It's a scarcity today but it's still one of the best mixers GLI ever made. At the time he wasn't using no cueing. In other words, the hole was there for a headphone to go in but I remember he never had headphones over his ears. All of a sudden, Herc had headphones but I guess he was so used to dropping the needle down by eyesight and trying to mix it that from the audio part of it he couldn't get into it too well.
- Grandmaster Flash - 1991 - by David Toop. Rap Attack 2: African Rap To Global Hip Hop, 62. New York: Serpent's Tail