Any conversation regarding the historical context of rap music will almost certainly rely heavily on the near ritualistic practice of sampling, essentially using older songs as the basis as the basis for new hip-hop music. Often it is stated that the beginnings of rap's musical source were from the records that were owned by the parents or older siblings of those who would become the first generation of DJs and MCs.
While this is certainly true, as I discuss a bit later, I also think that there is some further context that has to be given to how sampling, specifically within hip-hop culture, is always tied to a larger community that largely dictated the earliest sounds the genre took on.
While digging in the crates is certainly the practice at the center of hip-hop sampling, usually, at least in the beginning, the digging was not just for any random record.
The musical backing from back in the day
I will make the case for two different categories of sampling in rap music. Say you were a producer picking samples for a beat, and for a song you used one or two seconds of a horn riff from five minutes into a nine minute J. J. Johnson song from the mid 1960s. This in my opinion, is a related, but very different form of sampling than if you decided to sample "Scorpio" by Dennis Coffey & The Detroit Guitar Band.
The reason for the difference is that "Scorpio" was a known and popular b-boy song within hip-hop, being played at the early hip-hop parties thrown by DJ Kool Herc in the Bronx. The J. J. Johnson song could definitely be sampled, such as by someone like DJ Premier or Pete Rock, but that would be within an era in which rap records, and albums, had evolved to a point where production focused on more obscure and rare samples.
To be clear, producers of that era still referenced early hip-hop. Pete Rock's usage of vocals from T La Rock and Jazzy Jay's "It's Yours" from 1984 for the chorus of Nas' "The World Is Yours" from ten years later is one of numerous examples of '90s artists using lyrics and audio from '80s rap to build the thematic message of a song. This is important not only because Nas and Pete Rock grew up listening to '80s rap, but also because '80s artists provided the first template for how to make a rap record.
As far as it has gone in over 50 years, hip-hop music was centered on the DJ in the beginning. Since the DJ responds to the audience and has to understand what makes them move, this means hip-hop music was also in part shaped by the tastes of the audience, and what records were popular in the streets at that time.
During the first era of rap records in the late '70s and very early '80s, this reliance on hot records was very clear. Record labels like Sugar Hill, Enjoy, or Profile to name a few, often had producers and/or in-house bands that could replay and closely interpolate beats from popular disco, funk, rock, and electronic records, some that had commercial popularity and some that were popular more so in the hip-hop community, songs which at a party would have been played directly off the record by a DJ.
James Brown's "Funky President (People It's Bad)" from 1974 was one of these popular songs in the hip-hop community, and as such it was used as the foundation for Spoonie Gee's "Spoonie Is Back," from 1981, with production credit for Sylvia Inc. (I believe meaning Sylvia Robinson) and Jigsaw Prod. Inc., though the instrumentation may have been Sugar Hill's in-house band, which featured guitarist Skip McDonald, bass player Doug Wimbish, and the drummer Keith LeBlanc, amongst others.
Since 1981, "Funky President" has been sampled countless times by other rap acts following in Spoonie Gee's footsteps. However, as you probably know, many of the rap acts that succeeded Spoonie Gee did not need to utilize live musicians to replay the song. While the inspiration from these early records continued, the mode of production evolved, as by the late '80s it had become commonplace to simply sample "Funky President" directly onto your own song.
I will refer to JayQuan The Hip-Hop Historian's video on the "Golden Era" of hip-hop to explain the shift in hip-hop production in the 1980s, as he gives a great breakdown of all of the factors at play. To put it shortly, hip-hop sampling's legality has been an issue from the beginning, though early on it usually didn't matter as much since most early hip-hop records did not gain mainstream exposure and success.
Legal consequences were certainly a reality if something did become a hit, such as the Sugarhill Gang's "Rapper's Delight," which Sugar Hill Records was ultimately forced to rerelease with writing credits for Nile Rodgers and Bernard Edwards of Chic, as it was very blatantly interpolating their hit song "Good Times," which came out only a few months prior to "Rapper's Delight" in 1979.
However, probably more important than even this never ending question of legality, the mass shift in hip-hop production in the '80s was likely dependent on the creation of newer sampling technology and the cost of said technology catching up to the ingenuity of the hip-hop artists themselves.
In the early '80s, artists such as rap's first solo super star Kurtis Blow, who had a major record deal with Mercury/Polygram, had access to technology such as the Fairlight CMI (Computer Musical Instrument), which was a high end and very expensive piece of equipment capable of sampling.
There was also Just Allah the Superstar and Sedivine the Mastermind, the duo known as the World’s Famous Supreme Team, who had a radio show on WHBI-FM 105.9. They famously traveled to the United Kingdom in the early ‘80s to work with Malcolm McLaren and Trevor Horn, who also used upscale equipment like the Fairlight CMI and various machines from Oberheim on songs like 1982’s "Buffalo Gals” and “Hobo Scratch.” A 2013 article by Trevor Horn for Red Bull has more information.
To my understanding, it wouldn't be until around the mid '80s that more affordable and/or accessible samplers such as the E-mu SP-12, and it's follow up the SP-1200, would begin to emerge. These sampling drum machines are basically royalty within the hip-hop community, as they were utilized by many artists to loop drum breaks and other sounds directly from the record.
However, one of the pioneers of this shift in sampling in the mid '80s, DJ Marley Marl, did not use either of those pieces of equipment at the time in 1985. According to a 2013 video with "Dubspot" in which he recreates the beat to MC Shan's "The Bridge," his setup when creating the song consisted of two SDD-2000's (Sampling Digital Delay), made by Korg, and a Roland TR-808.
Marley was also not looping the drums for the song, instead taking the advice of his friend Claudio to use his two samplers to hold the kick and snare sounds, respectively, and triggering them through the TR-808, which I believe the sampler could plug into. Importantly, the drums for "The Bridge" were taken from "Impeach the President" by the Honey Drippers, while the other sample is a reversed sound from "Scratchin'" by the Magic Disco Machine.
Similar to the earliest hip-hop records, Marley's choice to use both "Scratchin'" and "Impeach The President" was based on his understanding that crowds loved these songs. His took his copy of "Scratchin" from his brother, I believe Larry Larr of the High Fidelity Crew, as he remembered the crowd response to that crew playing it. "Impeach The President" was a part of a batch of records he got in place of payment for production work from Aaron Fuchs, the founder of Tuff City Records.
Marley knew "Impeach The President" was popular in the streets, and the rest is history. I use this example of Marley Marl to point out that even as hip-hop moved forward and innovated itself, there was always a close connection to its earliest era and sounds. Other figures understood this as well, as in 1986 Street Beat Records began releasing classic break beat compilations called Ultimate Breaks & Beats, compiled by Leonard Roberts ("Breakbeat Lenny") and Louis Flores ("Breakbeat Lou").
Ultimate Breaks & Beats became immensely valuable to a new generation of hip-hop producers and DJs, not just on the East Coast, who now had access to many of the beats that formed the genre. Breakbeat Lou also edited and augmented the breaks on these compilations, making them easier to use and loop for aspiring DJs and producers. Basically, what had been initiated by New York DJs in the '70s, was by the mid '80s being actively spread to an even wider network of hip-hop artists.
I don't believe this connection to the past can ever be severed, but it might be safe to say the connection is most clear within these earlier eras. In a sense, the sample heavy production the Bomb Squad was doing in the late '80s would not be possible without Grandmaster Flash having first put his mastery of mixing records as a DJ on full display in 1981's "The Adventures of Grandmaster Flash on the Wheels of Steel."
While the Bomb Squad's work on "Night Of The Living Baseheads" is largely reliant on sampling equipment accompanied by some scratching, and "Adventures of Grandmaster Flash" focuses solely on Flash's skills on the turntables, their approaches to mixing together pieces from an array of songs are definitely linked.
To keep with this idea of links between eras, years before Marley Marl directly sampled "Ike's Mood I" for Biz Markie and T. J. Swan's "Make the Music with Your Mouth, Biz" in 1986, the Disco Four had rapped over an interpolation of the same section of Hayes' song in 1982's "We're at the Party," produced by Eric Matthew.
In the end, I believe innovation follows inspiration in hip-hop, and inspiration always comes from the community, as that is where hip-hop itself comes from. The inventiveness of the individuals will always be displayed, but the foundation they thrive upon are the people where they, and their ears, were developed.