I would say the first albums that I heard Frisell, which educated me on the use of looping in the context of group improvisation, would be _News For Lulu_ and _More News For Lulu_, both featuring Frisell, John Zorn, and George Lewis recasting bebop standards within a guitar/sax/trombone trio format. Can't recall what specific tracks he looped on.
Actually, the very first time I saw/heard of Frisell was on David Sanborn's _Sunday Night_ TV program, which came on after Saturday Night Live for an all-too-brief period of the late 80s. Don't recall if he used looping there.
those are 2 great albums-not sure about the looping on them tho'.
and frisell on that dave sanborn show?
he was aloopin w/ his trustee <EH16secddl>
i used to have video of that :-(