This is one of the tracks I recorded with Abe:
At 2:40, at the end of a "strum roll" phrase, he hit the last note sloppily. (If you listen to the next phrase after that, you can hear him do the same basic thing, but cleanly.) The engineer asked, "Should we do another take to fix that?", and Abe implored, "No! Leave it!"
Not because he was okay with being sloppy, but, as I understood him, because it added realism. Music isn't always flawless, and there's nothing wrong with that. We actually did do two takes of the song just to have options, but in the end we used the slightly flawed bit there, and I'm glad we did. Though his other take was brilliant in different ways!
I myself have been practicing his strum roll technique ever since then, eleven years now. Just recently I got to the point where I think I could realistically use the technique, in limited capacity; I am certainly not yet as proficient as Abe!
We also did a cover of the Koinonia tune "On My Way Home". At the time, the Koinonia albums were all out of print, though I think they are available digitally now. I wanted to help make some of those tunes accessible again. Abe did exactly one take, no overdubs, no false starts, just the one take. He was visibly emotional by the end, seemingly from happy memories.
I had done by best to transcribe the tune off the Koinonia record, but I was struggling. Before the session, Abe let me have a scanned copy of the original handwritten chart, he said, "Probably the only copy that exists!" I don't remember his exact words, but he agreed that some of Harlan's harmonies could be hard to hear into, and didn't seem surprised that I wasn't quite getting it on my own. In retrospect it seems a lot easier now, but it was still great to have the actual original chart to work with.