These are three of the most important moments in hiphop's development: 1979—Sugar Hill Gang's "Rapper's Delight" introduces rapping to a large audience; 1982—Run-D.M.C.'s "Sucker M.C.'s" introduces and sets the concrete boom-bap beat; and 1987—Eric B. & Rakim's "I Know You Got Soul" introduces the sampler. "Sucker M.C.'s," however, marks the real transition from disco rap to hiphop proper. Before "Sucker M.C.'s," rappers used breaks from live music, and so the only difference between hiphop and other forms of dance music was the rapping. Run-D.M.C. completed the break. After "Sucker M.C.'s," hiphop could be identified by its beat alone. "Sucker M.C.'s" is the true foundation of the last great black American art form.

Nearly 25 years later, Run-D.M.C. are defunct. Run, the lead rapper, is now a reverend; Jam Master Jay, the DJ, is dead; and DMC, the group's backbone, has released a solo album that bears the curious title Checks Thugs and Rock 'n' Roll, but none of the strength and force that defined his delivery when he was just a teenager.

Born Darryl McDaniels, DMC was the rock on which Run-D.M.C. stood. Run was quick and smart, Jam Master Jay was technical and resourceful, but DMC was the trio's truth and substance. It's not arbitrary that in "Sucker M.C.'s," DMC only appears near the end of the track. Run does most of the rapping, going on about what he owns, what his life is like, and other basic MC stuff. Then, with a minute left, while Jam Master Jay is cutting a record down to the bone, DMC announces: "I'm DMC in the place to be/I go to St. John's University/And since kindergarten I acquired the knowledge/And after 12th grade I went straight to college." No rapper today can, in one breath, say that he is a student in a Catholic college and sound as tough as the streets. 50 Cent would be dropped from his label in a minute if he dared to mention that he completed kindergarten.

In their prime, Run-D.M.C. were mind-blowing. Not only did they finalize the sound of hiphop, but they were the first to mix rap with traditional hard rock. "Rock Box" (1983) used thick rock guitars and a pounding rock beat. Indeed, theirs was a fearless hiphop, a hiphop without caution. This is why the first generation of hiphop headz has little to no interest in current rap; it's a hiphop that is, true, more violent, but is in fact filled with fear: It takes no risks, it can only do what has been done before, it must make loads of money or else it's the axe. But imagine releasing "Rock Box" in 1983! What the fuck were Run-D.M.C. thinking? Who in the world were they expecting to buy such a song? Most blacks were not into rock, and whites at the time were still discovering rap and had yet to constitute its main audience. But there it is: rock-rap. And if that weren't enough, the next album, King of Rock, was an even harder, more Spartan blend of the two genres.

Run-D.M.C.'s music was heavy, the leather they wore looked heavy, and the heaviest MC in the land was DMC. "I'm the king of rock," he declared at the opening of the title track of the album King of Rock, "there is no one higher/Sucker MCs should call me sire/To burn my kingdom, you must use fire/I won't stop rockin' till I retire...." This force, this authority is completely absent from DMC's new CD, Checks Thugs and Rock 'n' Roll, which, like Run-D.M.C.'s last album, 1999's Crown Royal, has lots of rock but none of the heaviness of, say, Raising Hell. DMC's delivery is lighter, his style of dress is lighter (Satan-grim black leather has been replaced by the kind of casual wear that would happily suit any Christian), and one track on the CD features the bird-light vocals of Sarah McLachlan. But maybe DMC can only be hard within the context of Run-D.M.C., and is a much softer personality when rapping solo. Whatever the case, I shall always have the deepest respect for the man who not only helped hiphop become hiphop, but who famously "stepped on stage/At Live AID/The people came/And the poor got paid."

charles@thestranger.com