Fifty-six-year-old Steven Stein professes to write about such topics as music, copyright laws, and politics on his infrequently updated Web log (www.steinski.com), but the truth is much more mercurial than that. Recent posts have included short blurbs on the PEN American Center, President Bush and disaster relief, a brief screed about the big business of scientific research, and download links to live DJ sets from Mr. Stein and his partner, Double Dee, aka Douglas DiFranco. This may sound like the digressions of a typical Web crawler, but the hodgepodge is a terrific encapsulation of the restlessly active mind behind some of the most trailblazing hip-hop and turntablism in pop history.

Believe it or not, 25 years ago, Mr. Stein was known as Steinski, a pioneering force in the controversial hip-hop style of record sampling and beat-making. That he happened to be an older Jewish man who worked in advertising when he made his music, rather than a young black kid growing up around block parties and nightclubs, didn’t seem to bother either him or the DJs playing his music one bit.

Today, the legendary — but never officially released — music from Steinski and Double Dee is finally receiving a proper release, on the pro-sampling label, Illegal Art. “What Does It All Mean? 1983-2006 Retrospective” collects the original Double Dee and Steinski mixes that simultaneously made their creators into pioneers and thieves, including “The Lessons” series (three groundbreaking remixes from the early-to-mid-’80s) and Steinski’s subsequent remix work, including his virtuosic 2003 remix album “Nothing To Fear.” Of course, it’s a near certainty that at least a few of the hundreds of samples appearing on this two-CD set have not been fully cleared by the appropriate legal licensing channels, but that’s as it should be if the music is truly to be appreciated. Steinski is a pastiche artist, and the entire world of recorded sound is his palette.

So how did a white ad man come to play a role in the birth of hip-hop? A quarter century ago, Messrs. Stein and DiFranco, a sound engineer for commercials, entered a contest organized by the upstart hip-hop and dance label Tommy Boy to remix G.L.O.B.E. and Whiz Kid’s “Play That Beat Mr. D.J.” The pair then spent 14 hours in Mr. DiFranco’s studio turning out five minutes and 23 seconds of music — created by cutting and splicing magnetic tape — that the judges (including such pillars of New York nightlife and radio mixes as Afrika Bambaataa, Shep Pettibone, and John “Jellybean” Benitez) deemed the winner.

That track, “Lesson 1: The Payoff Mix,” not only outlines Steinski and Double Dee’s blithe and engaging aesthetic, but pointed the way in which samples could and would be used in pop music forevermore, from the narrative sound fragments found in the work of Prince Paul, to the essay-like arrangements of D.J. Spooky and the broad collages riddling the work of Diplo and D.J. Shadow, to the radical mash-ups of Girl Talk that are popular in the underground today.

That “The Payoff Mix” hasn’t lost its own vitality is one of many factors that make “What Does It All Mean?” such a critical document. The track moves at the more languid cadence of early 1980s hip-hop, and some of the samples — including Culture Club, Yaz, Herbie Hancock’s “Rock It,” Malcolm McLaren’s “Buffalo Girls,” Indeep’s “Last Night a DJ Saved My Life” — certainly date it. But Messrs. Stein and DiFranco also smartly incorporated snippets from the Supremes, Little Richard, Martin Luther King Jr., Humphrey Bogart (dialogue from “Casablanca”), a dance instruction record, and an audio quote from Mayor Fiorello LaGuardia, who ends the track by asking, “And say, children, what does it all mean?”

This collection, which takes its title from that quote, attempts to answer that question. One potent answer lies in the skill and intelligence with which Messrs. Stein and DiFranco assembled their remixes. Each of the three chapters of “The Lessons” is a seamless, funky document overrun with wit, a genuine understanding of the ups and downs of a dance floor, and a sincere love of a wide range of genres. That’s why “The Lessons,” which was never released commercially, though it was played on the radio and sometimes in clubs, was so heavily bootlegged in the years before online file trading made finding obscure tracks a matter of a simple keyword search.

Aesthetically and intellectually, “The Lessons” still feels as much a part of the ongoing copyright wars because of how successfully Messrs. Stein and DiFranco recontextualized their sources into something entertaining, irreverent, and fresh. As Robert Christgau pointed out in a 1986 Village Voice essay, the organizing practice of “The Payoff Mix” isn’t much different from what the Dutch novelty act Stars on 45 did with their popular medleys, or what Dickie Goodman and Bill Buchanan did with their radio “break in” records, singles that used lyrics from popular songs in skit-like shorts.

As with those lesser examples of artistic scrounging, one shouldn’t consider “What Does It All Mean?” a rallying cry for open-sourced intellectual property; Mr. Stein’s mirthful music and freewheeling approach are refreshingly apolitical. Instead, consider it something far more volatile and necessary — a thriving, exciting example of the possibilities that can be realized when artists aren’t limited by the culture in which they work.