Well how? How did live albums change after it?

It made it possible for a live album to have 20+ minute jams.
Which live album prior to 1971 had a song that passed 20 minutes?

Well Live At The Apollo II has a 15 minute medley. Live/Dead has a 23 minute Dark Star. I don't think extending the maximum lenght of songs on a live albums is really much to shout about. I think if you're the kind of band who plays 20 minute live jams, your live albums will contain 20 minute live jams. I don't think it's a matter of ABB or anyone "making it possible".

I forgot about Live Dead. And about Apollo, those aren't 'improv jams' and you know it. Brown was doing medleys, not extending a studio song to 5 times it's regular length.

It's not a matter of making it possible.
It's a matter of making it possible on record.

Well there's also a 20 minute Mans Mans Mans World, which I'm pretty sure isn't a medley.

You haven't really said anything of any substance to counter what I said with those last two sentences.

Fine, I concede that the album should stay at #120.

Uh, yeah. From 20 to 120...wow, this discussion's all over the place, isn't it?

Anyway, I like the top twenty you've put together thus far, provided you put Exile below Are You Experienced and Nevermind like we talked about.

I think London Calling still take Nation of Millions. As long as musical impact equates to critical response from peers and the industry, aka acclaim, I feel Calling wins. Breakdown:

Influence: NoM, but by a bit. I'm leaning towards NoM, as people say musical impact being NoM affected rap, and rap being the apparently 'greater' genre (which I think is bull), it gets it. My argument would be NoM is the most influential rap album ever. London Calling is not the most influential punk album ever, though it does have some major influence, I don't think it compares to NoM. But London Calling did outstretch to many other groups and genres as a well listened and praised album, but I'm not sure if any of those bands in other genres took influence. So NoM.

Popularity: I think this was a criteria, and I'm pretty sure it's London Calling. Sales should show this.

Musical Impact/Acclaim: here's the confusing one. If this is in fact Acclaim, so peer and music industry response, it would be London Calling by quite a bit. London Calling is one of the most critically acclaimed and best reviewed albums of all time, way up there, probably top 10 most acclaimed albums. I hear nothing but greatness about it from any review or musician discussing the album. It get really high on lists strictly on it's acclaim. NoM was acclaimed by quite a few, and as time passes we will probably see even greater appreciation for it as rap grows, but as of now, London Calling takes Acclaim/Musical Impact by quite a large margin as far as I know.

So, it's 2:1 in favor of London, unless Influence trumps shit in which case it's 2:2 and I don't know what to do. Also, I feel London could take EP, it wins popularity and acclaim as well from what I know, however EP has some massive influence that might be great enough to put it ahead of LC. Don't know.

London Calling is praised by it's target demographic and every other person in the music industry when it came out and since. Like Nation, upon release LC was considered one of the greatest albums and not only saved the Clash, but made a huge storm throughout Britain, and definitely the US as well. I'm not even sure how big the impact of NoM was in Britain upon initial release, but I know LC was huge upon release in both countries.

I have been convinced by Deany and Georgi that Nation wins. Like you, we found musical impact to be the hardest to judge, but we concluded that it was fairly split, with no significant edge either way. I think LC takes popularity but LC might not actually be that influential, because most punk seems to draw more from the Sex Pistols. Influence for Nation is probably the biggest margin of any of the criteria.

There is no feasible argument for punk to be greater than hip-hop. Rap isn't just "apparently" the greater genre: it is.

Anyway, back to NoM vs. LC:

Influence: NoM by a galaxy. It influenced the entirety of hip-hop, from lyrical content to production style to sampling techniques. Considering that hip-hop is a very, very large and diverse subgenre, that's something. LC, on the other hand, has almost no influence to speak of, punk or otherwise. Most of the factors it incorporated were new to punk music, but no one in the genre was interested in equaling LC's scope. Most of punk's influence stems from Never Mind The Bollocks and the Clash's eponymous debut. Looking at rock's big picture, LC didn't really introduce anything new to the genre: double album, done; musical work, done; lyrical content, done.

Popularity: LC, but not even by half as much as NoM wins influence.

Musical Impact: Rap has probably grown way bigger than you think. The fact that every single hip-hop artist loves NoM (it's practically hip-hop's Bible, along with Raising Hell) pretty much trumps LC's acclaim, which is also very, very big. It's a matter of demographic, which plays a larger role than one might think.

Overall: NoM, by virtue of their massive influence lead and the iffyness of the Musical Impact of both.

Also, LC has no chance of beating EP by the criteria. None.

When I consider it, Abbey Road might beat London Calling. I'm sure it has a strong popularity lead. I would guess it could even trump LC's lead in musical impact, yielding a pretty good score there itself. Influence, I'm not really sure about, but like Deany and Georgi said, London Calling isn't actually THAT big in punk, influence wise. However, it is kinda hard for me to judge the influence of Beatles albums, as the tracks on them are usually very eclectric.

I'm sure Abbey Road gets some influence from the medley, though.