Possum

F7 funky w/bass notes (add sus4) F7
                F7 Thing
                  I come from atop the mountain baby

                  Where the people come to pray
                     Bb7 Thing
                  I come from atop the mountain baby
                                                              F7 Thing
                  Where the people come to pray
                             C7 Thing                      Ab
                  There ain't no truth in action
                                       Bb              F7 Thing
                  'Less you believe it anyway

                  I was riding down the road one day
                  And someone hit a possum
                  I was riding down the road one day
                  And someone hit a possum
                  The road was his end
                  His end was the road so they say
                          Whoa possum... possum, possum... POSSUM
                          Whoa possum... possum, possum... POSSUM
                          Whoa possum, possum
                          Your end is the road
                                     *Solo*

                  I was riding down the road one day
                  And someone hit a possum
                  I was riding down the road one day
                  And someone hit a possum
                  The road was his end
                  His end was the road so they say
                          Whoa possum... possum, possum... POSSUM
                          Whoa possum... possum, possum... POSSUM
                          Whoa possum
                          Your end is the road
                          Whoa possum, possum
                          Your end is the road

      

The riff I'm showing below is a standard folk strumming pattern, similar to the Dead's Cumberland Blues. Phish is playing with two guitars doing complimentary rhythm/leads. It sounds really good if you slide into the A & G strings of the chord. Or do a hammer-on on the G string. It also sounds really good if you play the F7 on the 8th fret. It's tough to tab out a jam band extensively because the music is improvisational and evolving, the leads are never the same, and in this case Trey eventually plays the guitar lines by himself (after the departure of Jeff.)

        
      F7 Thing: (F7 chord)
         e |----------------------
         B |---11----11---1111----
         G |---22----22---2322----
         D |---11----11---1111----
         A |------33--------------
         E |-1----------1---------
    

The Bb7 and C7 Things are very similar to the F Thing in that you do your your own bass lines. Add a sus 4th to the Bb7, but not the C7.