Epistemic status: probably we did lose the ability to memorize long songs due to improper practice, but it may be possible to enjoy the benefits of literacy and epic memory simultaneously.

Thanks to Niels uit de Bos for better links and editing, and to Ryan Kidd for encouragement to post.

You probably know that Socrates thought writing was terrible and it would destroy people’s ability to memorize things, because now they’re written down and don’t need to be memorized. I always thought that was a little ridiculous, maybe the effect was there and memorization would be less good, but not to a crazy extent.

Well, Milman Parry and Albert Lord traveled to Yugoslavia in the 1930-1950s, and recorded performance of gusle-player (guslar) bards. The greatest of them was Avdo Međedović. From Wikipedia:

At Parry’s request, Avdo sang songs he already knew and some songs he heard in front of Parry, convincing him that someone Homer-like could produce a poem so long. Avdo dictated, over five days, a version of the well-known theme The Wedding of Meho Smailagić that was 12,323 lines long, saying on the fifth day to Nikola (Parry’s assistant on the journey) that he knew even longer songs. On another occasion, he sang over several days an epic of 13,331 lines. He said he had several others of similar length in his repertoire. In Parry’s first tour, over 80,000 lines were transcribed.

All of the bards, which recited incredibly long songs from memory and composed slightly new lyrics on the fly “at the rate of [10-20] ten-syllable lines a minute”, and they could not have been geniuses, because there were too many of them. Instead, they had a “special technique of composition”: they were illiterate. From The Singer of Tales:

[Albert] Lord sees the existence of literacy and written/printed texts as deadly-- not to the songs themselves, but to the method of composition by which they are realised [which in the end amounts to the same thing]--schools, cities, and literacy eventually put [an end] to it in urban areas

“We must remember that the oral poet has no idea of a fixed model text to serve as his guide. He has models enough but they are not fixed and he has no idea of memorizing them in a fixed form. Every time he hears a song sung, it is different”

Once the idea that there is a fixed text enters the bard’s minds, they stop being able to compose new versions on the fly. Also presumably they can’t remember the full 13-thousand line epics because they won’t be able to remember the exact text.

Again from Wikipedia:

in 1935 Lord asked Međedović to recall a song he heard only once, for this he asked another guslar, Mumin Vlahovljak of Plevlje, to sing his song “Bećiragić Meho”, unknown to Međedović. After he heard the song of 2,294 lines, he sung it himself, but made it almost three times longer, 6,313 lines

I read about this from a blog post by Sam Kriss, and I was struck enough to fact-check it. The extent to which the memory and abilities of illiterate folks can be better than literate folks is very surprising to me.

It seems possible to me that literate people could replicate the feats of the guslar. But they'd have to hear the song many different times, sung somewhat differently by many different people, and resist the temptation to write it down to try to remember it as they learned. Lord's speculation on how to learn to be a bard:

We must remember that the oral poet has no idea of a fixed model text to serve as his guide. He has models enough but they are not fixed and he has no idea of memorizing them in a fixed form. Every time he hears a song sung, it is different." p.22 "Sometimes there are published versions of songs in the background. [Named Informant] in Bihac told us that he did not learn to sing until he was about twenty-eight (he was forty-five in 1935), and that he had learned his songs from the song books, the Matica Hrvatska collection in particular. Although he could not read, somebody had read them to him. He had also heard the older singers in his district. The entrance of these song books into the tradition is a very interesting phenomenon, and one that is open to gross misinterpretation. Yet as long as the singer himself remains unlettered and does not attempt to reproduce the songs word for word, these books have no other effect on him than that of hearing the song."

It may truthfully be said that the singer imitates the techniques of composition of his master or masters rather than particular songs. For that reason the singer is not very clear about the details of how he learned his art, and his explanations are frequently in very general terms. He will say that he was interested in the old songs, had a passion for them, listened to singers, and then, ‘work, work, work’ and little by little he learned to sing.