This thread has made me curious to pull out Joan's early albums to hear her approach to accompanying herself in her folk years. It's a nice, full guitar style, uncluttered with extra notes/chords. What she's doing really is not complicated. As someone else mentioned, she's mostly doing a variety of simple fingerpcking patterns, playing melodies within chords and walking bass. When someone feels their music deeply and puts in the practice, it shows in their playing. It's clear Joan was very committed to singing/playing in a style that suited her artistic expression.