I've now had the opportunity to look into this mystery first hand. We just got back from the National Thumbpicking Guitar Contest at the Ozark Folk Center in Mountain View, Arkansas, where Tommy Flint—the author in question—was one of the featured performers. Tommy seems to use this technique as a variation inside Travis/Atkins style numbers. He never used it for an entire piece either in concert or in the workshops.

Tommy uses thumb and three fingers to play this variation and keeps his little finger solidly braced on the guitar top. His picking hand is balled up quite like a Scruggs-style banjo player and the musical passages have the same melodic and rythmic feel as a chromatic bluegrass banjo played very fast. All the left hand work in these passages is higher up on the neck and often confined to the first four strings. I didn't see him “thumbing” his chords when using this technique.

I think Flint's crosspicking is an adaptation of the thumb and first finger rolls that thumbpickers such as Mose Rager, Merle Travis and Joel Maphis used a lot. He gets more variation because he uses a thumb and three fingers so his rolls aren't constrained by string order. The technique makes a nice variation for one chorus of a longer piece.

Tommy grew up in Muhlenberg County, Kentucky, and often went to Mose Rager's place to draw water from the fountain as it were. I sure wish I'd been smart enough to do that. <g>

      - Mark