I think that rap is sort of technology-based, and the technology in the early days was limited and sounds cheesy. I think the same thing about 80s synth-pop, but that stuff seems to be enjoying a great deal of “nostalgic” popularity these days. Which, BTW, is weird. Most people who actually had to endure the 80s have no love or nostalgia for that era, musically or otherwise, IMHO. Seriously, who thinks President Reagan, sideways hairdos, and preppy chic was a good thing?
Actually, if you go on Amazon and search for artists like Big Bill Broonzy and Robert Johnson, there are literally dozens of reissues and compilations available. New ones are released every year. They’re not at the top of the charts, but there is a substantial and lasting demand there.
That is because there aren’t very many dance oriented radio stations any more on FM radio. There is a lot of 90’s dance on satellite radio and it still gets some club play.
I respectfully beg to differ, Arky. I think whatever you grew up listening to, “the soundtrack of your youth” if you will, is usually the music you remember most fondly if not still listen to. I think the new wave / punk music of the eighties is the best, as far as *trends * go. I still listen to my old tapes(as opposed to the stuff you hear on '80s radio stations)and maybe I *am * just overcome with nostalgia, but I really do enjoy the music on its own merit.
Sorry to get off topic. I don’t know enough about rap to comment. Carry on.
One thing’s being overlooked here. Rap is still a dynamic & creative form. You still hear the envelope being pushed, with innovative records coming out every year. So maybe rap fans are too caught up in the present, trying to keep up with the new stuff. Maybe they’re spending all their money on the latest & don’t have any money to spend on the classics.
Rock fans buy '60s/'70s stuff because there is nothing exciting going on in rock today & probably won’t be again. It’s basically dead as an art form. Classic soul evolved into today’s R&B, but the change has been so drastic that '60s soul sounds like a completely different kind of music, hence you have a fanbase who are happy to keep going back to the old stuff. Country music at the commercial end has devolved into a grotesque, base kind of junk that many old-country fans sneer at; thus the George Joneses & Johnny Cashes etc. are still commercially valid.
Stop for a minute, baby I’m so glad you’re miiine!
Ever since the day you put my heart in motion,
Baby I realise that there’s just no getting over yooou!
*
Ah, seventh grade! What a time. 
This is probably indefensible, but I think that part of the reason is that RAP GOT A LOT BETTER.
Rock changed. Rap got better. I think you’d have a tough time convincing a lot of people that “Master of Puppets” is better than “Exile on Main Street”. But it was hard to listen to the earlier stuff, even Run DMC, after some of the stuff hit in the early 90s.
I think just about everybody on The Chronic or Doggystyle could do what Kool Moe Dee, or Beastie Boys, was doing, but not vice-versa.
Early on, the beats were simpler, the rapping and the rhymes were simpler.
Stuff that sounded good in the 80s sounded real stupid after Dre started making records. Didn’t Def Jam just get murdered by Death Row in the early 90’s? It wasn’t just a turf war that one side won. One side was light years ahead of the other in production quality, talent, etc.
Now, I tend to think that we’re reaching a point where there aren’t great advances being made. I don’t think the big sellers from recent years. . .Kanye West, Fitty Cent, Jay-Z or more cutting edge guys (“Dead Prez” maybe, I’m really not too up on it) are really more talented than the early 90’s’ guys.
“The Chronic” and “Doggystyle” and “2Pacalypse” will always be listened to. “Hammer Time”. . .not so much.
The day “Hammer Time” is considered classic rap is the day I walk into a random McDonald’s and start blowing everyone away with a urine-filled Supersoaker screaming, “You can’t TOUCH this! You can’t TOUCH this!”
While others have mentioned some relevant things, I think that **Ellis Aponte Jr. ** is closest to the right answer. Rap isn’t quite ready for a nostalgic revival yet. The commerical audience who grew up listening to “The Message” rap as children and “How Can I Move The Crowd” and “Microphone Fiend” as young teenagers and remembers where they were when Rozanne Shante and UTFO dropped one of the first rap wars isn’t ready for wide-scale musical nostalgia yet.
When rappers get nostalgic, it’s about the era and the culture, not so much the music alone. Some artists give homage to the era in misty terms (I’m looking at you Lauryn Hill – “Every Ghetto, Every City”), or scars earned in music battles fought and won (Dr. Dre’s “Hello”).
The Dust Brothers, not so much. Paul’s Boutique is lightyears ahead of anything I’ve heard before or since in rap.
There are several problems hurting the sales of “classic rap”. Virtually every area has a classic rock or oldies station;indeed, you’re more likely to be exposed to classic rock than contemporary rock. With the exception of “old school” hours on hip-hop stations, early rap gets far less exposure. Also, rap in its early years was a niche music, so relatively few people grew up with it and thus it doesn’t have the nostalgia value of oldies or disco. Plus, rappers have always had short commercial lifespans and therefore don’t have lengthy catalogs. I think this will change, as today’s rap will be 20 years from now a nostalgia music.
Gee, I listen to classic rap all the time on The Rhyme on XM. There is some Hip-Hop stuff they play I don’t like, but you can usually get Eric B and Rakim, The Funky Four plus One, UTFO, Run-Dmc, and LL when he was good. There was a lot of junk in those days though, and sometimes that’s reflected.
I would think that there just isn’t enough of a well to draw from right now. There was a lot of bad early hip-hop and rap, and a lot of people jumping in to make a quick buck. So while there are some true pearls, there isn’t always enough to fill time. While I enjoy the Rhyme, it can fall into this same trap. I hate having the stupid Sugarhill Gang on for twenty minutes.
“Rapper’s Delight” is a terrible song.
It’s a half-step removed from a dude going,
*My name is Trunk, and I’m here to say
I like making rhymes, ever-ee day.
*
I like your style, kid. How would you like a record deal? 
But seriously, I don’t think rap really hit its stride as a genre until at least the late 80s and early 90s (obviously, there were two or three artists/groups who were exceptions to the rule). I think that one of the criteria for calling something classic is that you can introduce it to later generations or people previously unfamiliar with the genre who would be able to develop an appreciation for it. As Askia alluded to, I don’t know that there are a lot of pre-teens now who would learn to love rap based on listening to “Please Hammer, Don’t Hurt 'Em” (nor would I wish to foist that on another generation, frankly).
And now, I think I’m going to listen to Public Enemy’s “Apocalypse '91: The Enemy Strikes Black” to get my work day started, if you’ll excuse me.
The OP is starting from an incorrect premise. Everybody my age has Rapper’s Delight in their collection. Or Straight Outta Compton or some Grandmaster Flash. But then again, everyone I know was listening when this stuff came out.
Or maybe by ‘less popular’ the OP means why don’t white people listen to classic rap?
Biggirl, everyone your age may have Rapper’s Delight in their collection, but my guess would be it is an origianal copy they bought in 1979, and that very few of them recently spent 18.98 on the CD. I would also guess that the don’t pull it and rock it from their car CD player very often either. Hell, I may have a copy of it somewhere, even though I’m not a fan.
I’m not sure where you’re coming from on the race thing. As I stated in the OP, I am no rap fan. I have, though, liked certain songs here and there. But part of the basis for my OP was my noticing that even among my rap loving friends, white and black, almost all agreed with my assessment that they rarely, if ever, pull out a pre Straight Outta Compton CD and play it.
Of the 30 or so responses to the OP, some of which I assume are black, few if any disagreed with my premise, so I don’t think it is faulty. You may have Big Daddy Kane’s best playing right now, and your clique may as well, but you and your friends don’t automatically represent the whole. And your observation of white people not listening to rap is pretty myopic.
Yes, my friends and I don’t make up the whole-- just as your friends and you do not either. Of course, my telling you that there are people who listen to Grandmaster Flash about as often as they listen to Abbey Road will mean nothing to you if you’ve already made up your mind that classic rap is less popular than other genres.
I can readily admit a mistake if wrong, but in this case, lacking defentive data
on either side, I guess we’ll have to agree to disagree, no hard feelings.
But…just as a reference:
Amazon sales rank of the most popular Grandmaster Flash CD- #40,492
Abbey Road- #111
And to expand further. . . where is this idea that old school rap isn’t popular coming from? I mean, it even has it’s own name-- do you not hear people talk about Old School all the time? Afrika Bambaata, Marley Marl, Soul Sonic Force are practically revered in hip hop.
People who listen to rap know these people and these songs just as well as punk guys know The Ramones and The Clash. What is it that you mean by ‘not popular’?
How many records did each sell in their original run? Do you expect classic rap to sell more records than it did when it first came out?
It’s looking more and more to me that you really do mean popular with white people.
Two quantities:
Classic rap’s popularity RELATIVE to modern hip-hop.
Classic rock’s popularity RELATIVE to modern rock.
Do you think those things are equal?
I think that all the OP is saying that while U2 and Jay-Z might both sell 1 million copies today, there’s no way that Erik B & Rakim is selling as many albums as “Exile on Main Street”.
You can factor race out of it.